Copyright for pkg-config source package in Xenial

This is the Debian package of freedesktop.org pkg-config.

Copyright (C) 2001, 2002 Red Hat Inc.
Copyright (C) 2004, 2005 Tollef Fog Heen 

License:

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.

On Debian GNU/Linux systems, the complete text of the GNU General Public
License can be found in `/usr/share/common-licenses/GPL'.