Debian packaging improvements

Some small changes to make the Riemann deb nicer to work with.
It still doesn't work to run `fakeroot lien fatdeb`, for instance, but if Leiningen invokes fakeroot as a subprocess when it calls dpkg-deb to assemble the deb, as far as I can tell that actually works fine. Apologies if I'm missing something that is still a blocker here.