use /dev/null as HTML_FOOTER to prevent footer generation for not bloating commit diffs (can be reversed later)
cpack/deb: fixed some lintian errors (still preliminary)
cpack/deb: fixed debian description
cpack/deb: fixed lintian warning missing-pre-dependency-on-multiarch-support
use PACKAGE_DESCRIPTION as brief summary text
add docs target to ALL target, closes #62