Copyright for mpc source package in Focal

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: mpc
Source: https://www.musicpd.org/clients/mpc/
Upstream-Contact: Max Kellermann 

Files: *
Copyright: 2003-2018, The Music Player Daemon Project (see AUTHORS for details)
License: GPL-2+

Files: debian/*
Copyright: 2003-2004, Warren Dukes (aka shank) 
 2004-2005, Eric Wong 
 2006-2011, Decklin Foster 
 2011-2012, Alexander Wirt 
 2013-2019, Florian Schlichting 
License: GPL-2+

Files: debian/examples/playstream
Copyright: 2006, martin f. krafft 
License: Artistic
 This program is free software; you can redistribute it and/or modify
 it under the terms of the Artistic License, which comes with Perl.
 .
 On Debian systems, the complete text of the Artistic License can be
 found in `/usr/share/common-licenses/Artistic'.

License: GPL-2+
 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, or (at your option)
 any later version.
 .
 On Debian systems, the complete text of version 2 of the GNU General
 Public License can be found in `/usr/share/common-licenses/GPL-2'.