simplify Debian packaging

Created by: lnussbaum

Hi,

This PR changes the Debian packaging. It merges the packaging code in the master branch, then turns the package into a "native" one. This makes it unsuitable for direct inclusion in Debian, but also makes it much more simple.

See "rake debian", or just run "rake debian | sh" to generate the two flavors of packages.

This makes all branches unnecessary.