Cleanup the debian packaging.

And re-add the 2.x era changelog of the package.
Clean the debian package of unclear licensed material.

In passing, fix the clean target too.
Clean up debian packaging.

The licensing of some of the test material being unclear, make a +dfsg
source archive and packages, also clean up several items that shouldn't
be part of the final debian package (.vagrant, etc).

Thanks Christoph Berg for the review!