LICENSE

                    GNU GENERAL PUBLIC LICENSE
                       Version 3, 29 June 2007

 Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

 Preamble

 The GNU General Public License is a free, copyleft license for
 software and other kinds of works.

 The licenses for most software and other practical works are designed
 to take away your freedom to share and change the works. By contrast,
 the GNU General Public License is intended to guarantee your freedom to
 share and change all versions of a program--to make sure it remains free
 software for all its users. We, the Free Software Foundation, use the
 GNU General Public License for most of our software; it applies also to
 any other work released this way by its authors. You can apply it to
 your programs, too.

 When we speak of free software, we are referring to freedom, not
 price. Our General Public Licenses are designed to make sure that you
 have the freedom to distribute copies of free software (and charge for
 them if you wish), that you receive source code or can get it if you
 want it, that you can change the software or use pieces of it in new
 free programs, and that you know you can do these things.

 To protect your rights, we need to prevent others from denying you
 these rights or asking you to surrender the rights. Therefore, you have
 certain responsibilities if you distribute copies of the software, or
 if you modify it: responsibilities to respect the freedom of others.

 For example, if you distribute copies of such a program, whether
 gratis or for a fee, you must pass on to the recipients the same
 freedoms that you received. You must make sure that they, too, receive
 or can get the source code. And you must show them these terms so they
 know their rights.

 Developers that use the GNU GPL protect your rights with two steps:
 (1) assert copyright on the software, and (2) offer you this License
 which gives you legal permission to copy, distribute and/or modify the
 software.

 Also, for each author's protection and ours, we want to make certain
 that everyone understands that there is no warranty for this free
 software. If the software is modified by someone else and passed on, we
 want its recipients to know that what they have is not the original, so
 that any problems introduced by others will not reflect on the
 original authors' reputations.

 Finally, any free program is threatened constantly by software
 patents. We wish to avoid the danger that redistributors of a free
 program will individually obtain patent licenses, in effect making the
 program proprietary. To prevent this, the GPL assures that patents
 cannot be used to render the program non-free.

 The precise terms and conditions for copying, distribution and
 modification follow.

                    TERMS AND CONDITIONS

 0. Definitions.

 "This License" refers to version 3 of the GNU General Public License.

 "Copyright" also means copyright-like laws that apply to other kinds
 of works, such as semiconductor masks.

 "The Program" refers to any copyrightable work licensed under this
 License. Each licensee is addressed as "you". "Licensees" and
 "recipients" may be individuals or organizations.

 To "modify" a work means to copy from or adapt all or part of the work
 in a fashion requiring copyright permission, other than the making of an
 exact copy. The resulting work is called a "modified version" of the
 earlier work or a work "based on" the earlier work.

 A "covered work" means either the unmodified Program or a work based
 on the Program.

 To "propagate" a work means to do anything with it that, without
 permission, would make you directly or secondarily liable for
 infringement under applicable copyright law, except executing it on a
 computer or modifying a private copy. Propagation includes copying,
 distribution (with or without modification), making available to the
 public, and in some countries other activities as well.

 To "convey" a work means any kind of propagation that enables other
 parties to make or receive copies. Mere interaction with a user through
 a computer network, with no transfer of a copy, is not conveying.

 An interactive user interface displays "Appropriate Legal Notices"
 to the extent that it includes a convenient and prominently visible
 feature that (1) displays an appropriate copyright notice, and (2)
 tells the user that there is no warranty for the work (except to the
 extent that warranties are provided), that licensees may convey the
 work under this License, and how to view a copy of this License. If
 the interface presents a list of user commands or options, such as a
 menu, a prominent item in the list meets this criterion.

 1. Source Code.

 The "source code" for a work means the preferred form of the work for
 making modifications to it. "Object code" means any non-source form
 of a work.

 A "Standard Interface" means an interface that either is an official
 standard defined by a recognized standards body, or, in the case of
 interfaces specified for a particular programming language, one that
 is widely used among developers working in that language.

 The "System Libraries" of an executable work include anything, other
 than the work as a whole, that (a) is included in the normal form of
 packaging a Major Component, but which is not part of that Major
 Component, and (b) serves only to enable use of the work with that
 Major Component, or to implement a Standard Interface for which an
 implementation is available to the public in source code form. A "Major
 Component", in this context, means a major essential component (kernel,
 window system, and so on) of the specific operating system (if any) on
 which the executable work runs, or a compiler used to produce the work,
 or an object code interpreter used to run it.

 2. Basic Permissions.

 All rights granted under this License are granted for the term of
 copyright on the Program, and are irrevocable provided the stated
 conditions are met. This License explicitly affirms your unlimited
 permission to run the unmodified Program. The output from running a
 covered work is covered by this License only if the output, given its
 content, constitutes a covered work. This License acknowledges your
 rights of fair use or other equivalent, as provided by copyright law.

 3. Protecting Users' Legal Rights From Anti-Circumvention Law.

 No covered work shall be deemed part of an effective technological
 protection measure under any applicable law fulfilling obligations under
 article 11 of the WIPO copyright treaty adopted on 20 December 1996, or
 similar laws prohibiting or restricting circumvention of such
 measures.

 4. Conveying Verbatim Copies.

 You may convey verbatim copies of the Program's source code as you
 receive it, in any medium, provided that you conspicuously and
 appropriately publish on each copy an appropriate copyright notice;
 keep intact all notices stating that this License and any
 non-permissive terms added in accord with section 7 apply to the code;
 and give all recipients a copy of this License along with the Program.

 5. Conveying Modified Source Versions.

 You may convey a work based on the Program, or the modifications to
 produce it from the Program, in the form of source code under the
 terms of section 4, provided that you also meet all of these
 conditions:

 a) The work must carry prominent notices stating that you modified
    the work and giving a relevant date.

 b) The work must carry prominent notices stating that it is released
    under this License and any conditions added under section 7. This
    requirement includes the requirement to ensure that the modified
    work, in source code form, carries prominent notices stating that
    you changed the files and the dates of any change.

 c) You must license the entire work, as a whole, under this License
    to anyone who comes into possession of a copy. This License will
    therefore apply, along with any applicable section 7 additional
    terms, to the whole of the work, and all its parts, regardless of
    how they are packaged. This License gives no permission to license
    the work in any other way, but it does not invalidate such
    permission if you have separate permission to do so.

 d) If the work has interactive user interfaces, each must display
    Appropriate Legal Notices; however, if the Program has interactive
    interfaces that do not display Appropriate Legal Notices, your
    work need not make them do so.

 A compilation of a covered work with other separate and independent
 works, which are not by their nature extensions of the covered work,
 and which are not combined with it such as to form a larger program,
 in or on a volume of a storage or distribution medium, is called an
 "aggregate" if the compilation and its resulting copyright are not
 used to limit the access or legal rights of the compilation's users
 beyond what the individual works permit. Inclusion of a covered work
 in an aggregate does not cause this License to apply to the other
 parts of the aggregate.

 6. Conveying Non-Source Forms.

 You may convey a covered work in object code form under the terms of
 sections 4 and 5, provided that you also convey the machine-readable
 Corresponding Source under the terms of this License, in one of the
 following ways:

 a) Convey the object code in, or embodied in, a physical product
    (including a physical distribution medium), accompanied by the
    Corresponding Source fixed on a durable physical medium customarily
    used for software interchange.

 b) Convey the object code in, or embodied in, a physical product
    (including a physical distribution medium), accompanied by a
    written offer, valid for at least three years and valid for as
    long as you offer spare parts or customer support for that product
    model, to give anyone who possesses the object code either (1) a
    copy of the Corresponding Source for all the software in the
    product that is covered by this License, on a durable physical
    medium customarily used for software interchange, for a price no
    more than your reasonable cost of physically performing this
    conveying of source, or (2) access to copy the
    Corresponding Source from a network server at no charge.

 c) Convey individual copies of the object code with a copy of the
    written offer to provide the Corresponding Source. This alternative
    is allowed only occasionally and noncommercially, and only if you
    received the object code with such an offer, in accord with
    subsection 6b.

 d) Provide access from a designated place ("network server") where
    the object code and Corresponding Source are both available, provided
    that you convey the object code by offering access from that same
    place to anyone who possesses the object code.

 e) Convey the object code using peer-to-peer transmission, provided
    you inform other peers where the object code and Corresponding
    Source of the work are being offered to the general public at no
    charge under subsection 6d.

 A separable portion of the object code, whose source code is excluded
 from the Corresponding Source as a System Library, need not be
 included in conveying the object code work.

 7. Additional Terms.

 "Additional permissions" are terms that supplement the terms of this
 License by making exceptions from one or more of its conditions.

 Additional permissions that are applicable to the entire Program shall
 be treated as though they were included in this License, to the extent
 that they are valid under applicable law. If additional permissions
 apply only to part of the Program, that part may be used separately
 under those permissions, but the entire Program remains governed by
 this License without regard to the additional permissions.

 When you convey a copy of a covered work, you may at your option
 remove any additional permissions from that copy, or from any part of
 it. (Additional permissions may be written to require their own
 removal in certain cases when you modify the work.) You may place
 additional permissions on material, added by you to a covered work,
 for which you have or can give appropriate copyright permission.

 Notwithstanding any other provision of this License, for material you
 add to a covered work, you may (if authorized by the copyright holders
 of that material) supplement the terms of this License with terms:

 a) Disclaiming warranty or limiting liability differently from this
    License; or

 b) Requiring preservation of specified reasonable legal notices or
    author attributions in that material or in the Appropriate Legal
    Notices displayed by works containing it; or

 c) Prohibiting misrepresentation of the origin of that material, or
    requiring that modified versions of such material be marked in
    reasonable ways as different from the original version; or

 d) Limiting the use for publicity purposes of names of licensors or
    authors; or

 e) Declining to grant rights under trademark law for use of some
    trade names, trademarks, or service marks; or

 f) Requiring indemnification of licensors and authors of that
    material by anyone who conveys the material (or modified versions of
    it) with contractual assumptions of liability to the recipient, for
    any liability that these contractual assumptions directly impose on
    those licensors and authors.

 All other non-permissive additional terms are considered "further
 restrictions" within the meaning of section 10. If the Program as you
 received it, or any part of it, contains a notice stating that it is
 governed by this License along with a term that is a further
 restriction, you may remove that term. If a license document contains
 a further restriction but permits relicensing or conveying under this
 License, you may add to a covered work material governed by the terms
 of that license, provided the further restriction does not survive
 such relicensing or conveying.

 8. Termination.

 You may not propagate or modify a covered work except as expressly
 provided under this License. Any attempt otherwise to propagate or
 modify it is void, and will automatically terminate your rights under
 this License (including any patent licenses granted under the third
 paragraph of section 11).

 However, if you cease all violation of this License, then your
 license from a particular copyright holder is reinstated (a)
 provisionally, unless and until the copyright holder explicitly and
 finally terminates your license, and (b) permanently, if the copyright
 holder fails to notify you of the violation by some reasonable means
 prior to 60 days after the cessation.

 Moreover, your license from a particular copyright holder is
 reinstated permanently if the copyright holder notifies you of the
 violation by some reasonable means, this is the first time you have
 received notice of violation of this License with respect to the
 particular work, and you cure the violation prior to 30 days after
 your receipt of the notice.

 Termination of your rights under this section does not terminate the
 licenses of parties who have received copies or rights from you under
 this License. If your rights have been terminated and not permanently
 reinstated, you do not qualify to receive new licenses for the same
 material under section 10.

 9. Acceptance Not Required for Having Copies.

 You are not required to accept this License in order to receive or run
 a copy of the Program. Ancillary propagation of a covered work
 occurring solely as a consequence of using peer-to-peer transmission
 to receive a copy likewise does not require acceptance. However, nothing
 other than this License grants you permission to propagate or modify
 the Program or its derivative works. These actions infringe copyright
 if you do not accept this License. Therefore, by modifying or
 propagating a covered work, you indicate your acceptance of this
 License to do so.

 10. Automatic Licensing of Downstream Recipients.

 Each time you convey a covered work, the recipient automatically
 receives a license from the original licensors, to run, modify and
 propagate that work, subject to this License. You are not responsible
 for enforcing compliance by third parties with this License.

 11. Patents.

 A "contributor" is a copyright holder who authorizes use under this
 License of the Program or a work on which the Program is based. The
 work thus licensed is called the contributor's "contributor version".

 A contributor's "essential patent claims" are all patent claims
 owned or controlled by the contributor, whether already acquired or
 hereafter acquired, that would be infringed by some manner, permitted
 by this License, of making, using, or selling its contributor version,
 but do not include claims that would be infringed only as a result of
 further modification of the contributor version. For purposes of this
 definition, "control" includes the right to grant patent sublicenses
 in a manner consistent with the requirements of this License.

 Each contributor grants you a non-exclusive, worldwide, royalty-free
 patent license under the contributor's essential patent claims, to
 make, use, sell, offer for sale, import and otherwise run, modify and
 propagate the contents of its contributor version.

 In the following three paragraphs, a "patent license" is any express
 agreement or commitment, however denominated, not to enforce a patent
 (such as an express permission to practice a patent or covenant not to
 sue). To the extent that a license under such a claim is given by a
 contributor, the corresponding contributor's patent license is
 sublicensable. If you convey a covered work, knowingly relying on a
 patent license, and the corresponding source of the patent license is
 not available from the contributor, you must either (1) cause the
 patent license to be made available for the recipients, or (2) make a
 good faith effort to arrange to provide the patent license yourself.

 If, under reasonable claims, you have actual knowledge that the
 Program or a contributor version thereof, from the contributor's own
 standpoint, is infringing a patent, then you must either (a) refrain
 from propagating the work or modifying it, or (b) contact the
 contributor and obtain a patent license, or (c) stop distributing the
 Program. This requirement does not invalidate any other obligations
 under this License.

 If you convey a covered work, knowingly relying on a patent license,
 and the corresponding source of the patent license is not available
 from the contributor, you must either (1) cause the patent license to
 be made available for the recipients, or (2) make a good faith effort
 to arrange to provide the patent license yourself. This provision is
 intended to ensure downstream recipients have access to the patents
 that the contributor relied upon when making the software available.

 12. No Surrender of Others' Freedom.

 If conditions are imposed on you (whether by court order, agreement or
 otherwise) that contradict the conditions of this License, they do not
 excuse you from the conditions of this License. If you cannot convey
 a covered work so as to satisfy simultaneously your obligations under
 this License and any other pertinent obligations, then as a
 consequence you may not convey it at all. For example, if a patent
 license would not permit royalty-free redistribution of the Program by
 all those who receive copies directly or indirectly through you, then
 the only way you could satisfy both it and this License would be to
 refrain entirely from distribution of the Program.

 13. Use with the GNU Affero General Public License.

 Notwithstanding any other provision of this License, you have
 permission to link or combine any covered work with a work licensed
 under version 3 of the GNU Affero General Public License into a single
 combined work, and to convey the resulting work. The terms of this
 License will continue to apply to the part which is the covered work,
 but the special requirements of the GNU Affero General Public License,
 section 13, concerning interaction through a network will apply to the
 combination as such.

 14. Revised Versions of this License.

 The Free Software Foundation may publish revised and/or new versions
 of the GNU General Public License from time to time. Such new versions
 will be similar in spirit to the present version, but may differ in
 detail to address new problems or concerns.

 Each version is given a distinguishing version number. If the Program
 specifies that a certain numbered version of the GNU General Public
 License "or any later version" applies to it, you have the option of
 following the terms and conditions either of that numbered version or
 of any later version published by the Free Software Foundation. If the
 Program does not specify a version number of the GNU General Public
 License, you may choose any version ever published by the Free Software
 Foundation.

 If the Program specifies that a proxy can decide which future
 versions of the GNU General Public License can be used, that proxy's
 public statement of acceptance of a version permanently authorizes you
 to choose that version for the Program.

 15. Disclaimer of Warranty.

 THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
 APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
 HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT
 WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT
 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
 OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU
 ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

 16. Limitation of Liability.

 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR
 CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
 INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES
 ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT
 NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSS
 OF BUSINESS PROFITS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN
 ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

 17. Interpretation of Sections 15 and 16.

 If the disclaimer of warranty and limitation of liability provided
 above cannot be given local legal effect according to their terms,
 reviewing the interpretation of the local law may be necessary. In
 such case, the intent of the parties and the underlying purpose of the
 GNU GPL should guide the interpretation.

 END OF TERMS AND CONDITIONS

 How to Apply These Terms to Your New Programs

 If you develop a new program, and you want it to be of the greatest
 possible use to the public, the best way to achieve this is to make it
 free software which everyone can redistribute and change under these
 terms.

 To do so, attach the following notices to the program. It is safest
 to attach them to the start of each source file to most effectively
 state the exclusion of warranty; and each file should have at least
 the "copyright" line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.

 Also add information on how to contact you by electronic and paper
 mail.

 If the program does terminal interaction, make it output a short
 notice like this when it starts in an interactive mode:

    "<program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details." 

 The hypothetical commands `show w' and `show c' should show the
 appropriate parts of the General Public License. Of course, the
 commands you use may be called something other than `show w' and `show c'.

 You should also get your employer (if you work as a programmer) or
 school, if any, to sign a "copyright disclaimer" for the program,
 if necessary.  For more information on this, and how to apply and
 follow the GNU General Public License, see <https://www.gnu.org/licenses/>.