packaging improvements

* add versioneer (patched for our particular repo config)
* add parse_requirements to unify requirement handling
Merge remote-tracking branch 'kali/feature/improve_packaging' into develop
Fold in changes
Merge tag '0.3.1' into debian-rel0.3.1

Tag leap.soledad version 0.3.1
bump version
Fix pydist-overrides
Remove the hard-dep on six

It looks like it is no longer needed, but leaving it commented
until we do some more tests.
updated changelog
Merge pull request #66 from kalikaneko/debian-rel0.3.1

Debian rel0.3.1