Change FreeIPA license to GPLv3+

The changes include:
 * Change license blobs in source files to mention GPLv3+ not GPLv2 only
 * Add GPLv3+ license text
 * Package COPYING not LICENSE as the license blobs (even the old ones)
   mention COPYING specifically, it is also more common, I think

 https://fedorahosted.org/freeipa/ticket/239

doc/examples/python-api.py

@@ -1,4 +1,23 @@
 #!/usr/bin/env python
+# Authors:
+#   Jason Gerard DeRose <jderose@redhat.com>
+#
+# Copyright (C) 2009  Red Hat
+# see file 'COPYING' for use and warranty information
+#
+# 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 <http://www.gnu.org/licenses/>.
+#
 
 from ipalib import api