Disable silent builds so blhc can check for hardening flags
Add Vcs-* headers to control file (Closes: #751999)

Suggested-By: Michael Biebl <biebl@debian.org>
Mark binary packages as linux-only (Closes: #752000)

libndp is using linux-only features (like signalfd), so it FTBFS on
non-linux architectures.

Mark packages as linux-only pending a possible port to non-linux
architectures.
Update changelog for 1.2-5 release