debian: move ubuntu 16.04 files into new backports system
Added 'debian/patches' to the exclude file, since the existing patches
interfere with the build and are unused by our build. No other
changes were necessary. Used '-0~ubuntu16.04+1' as the version
extention, to denote: no patches (-0), debian packaging files changed
for backport (+1).
Signed-off-by: Silas McCroskey <smccroskey@cumulusnetworks.com> Signed-off-by: Martin Winter <mwinter@opensourcerouting.org>