This commit updates all authorship and copyright information to include a
standard header that references the AUTHORS and CREDITS file. This standard
header was written by the Debian legal team at the request of Franck Joncourt.
Applied a patch sent from Jonathan Bennett to add fwknop-2.0.0rc2 support to
openwrt. One thing to note about this patch is that the +libgdbm library
dependency has been removed because fwknop now implements its own digest
tracking file without needing gdbm/ndbm on the system.
