CP-5784: Move blktap packaging files to blktap repository

Currently packaging (Makefile, spec and other related files) are in
guest-packages.hg. Many components depends from blktap so every time
guest-packages.hg is changed this cause rebuilding blktap and every
component depending on it. Mostly of the other components have these
kind of files in the same repository.

Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
Merge pull request #45 from freddy77/include_build

CP-5784: Move blktap packaging files to blktap repository

Reviewed-by: Thanos Makatos <thanos.makatos@citrix.com>