Copyright for pdmenu source package in Xenial

Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/

Files: *
Copyright: Copyright (c) 1995-2011 Joey Hess 
License: GPL-2+
 The full text of the GPL is distributed as doc/COPYING in pdmenu's source,
 and is distributed in /usr/share/common-licenses/GPL-2 on Debian systems.