Clarify license conditions (GPL2+)

This does not change the license. It always was GPL2+.

Signed-off-by: Michael Buesch <[email protected]>

COPYING.txt

@@ -1,4 +1,19 @@
-                    GNU GENERAL PUBLIC LICENSE
+Awlsim license conditions:
+
+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 2 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.
+
+=============================================================================
+
+
+		    GNU GENERAL PUBLIC LICENSE
                        Version 2, June 1991
 
  Copyright (C) 1989, 1991 Free Software Foundation, Inc.,

tests/COPYING.txt

@@ -0,0 +1,11 @@
+All awlsim unit-tests are covered by the following license conditions:
+
+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 2 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.