Copyright for xl2tpd source package in Bionic

Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Source: http://www.xelerance.com/software/xl2tpd/ (repacked to remove non-free RFC text included in upstream distribution)

Files: *
Copyright: (c) 2006-2016 Xelerance Corporation
License: GPL-2+

Files: debian/*
Copyright: (c) 2007-2013 Roberto C. Sanchez 
                         Jean-Francois Dive
License: GPL-2+

License: GPL-2+
 Please see the CREDITS file for a complete copyright history of all parts of
 the project.
 .
 On Debian systems, the complete text of the GNU General
 Public License can be found in `/usr/share/common-licenses/GPL-2'.