Beta for real

This is the first feature-complete version of the Virtualmin 6 installer (it probably doesn't work everywhere, but when it does work, it probably results in a fully functional Virtualmin 6 system, or very close to it).

New features since the last roll:

• Firewalld - Sets up a new firewall with firewalld, blocking everything except the ports and services needed for hosting. There's been some upgrades to the Webmin Firewalld module to make managing rules nicer...some of those aren't actually in the released Webmin yet, but will be in a day or two.
• Fail2ban - Sets up fail2ban to monitor most of the services in a Virtualmin system, including Webmin and ssh logins, some mail logins, etc.

It's probably broken in fun ways, so file tickets if you find them.