Support 'gpgsig' property in Commit objects.
Test ProtocolGraphWalker.all_wants_satisfied rather than private
_is_satisfied.
Add missing underscore in test name.
Factor out all_wants_satisfied.
Remove setuptools 2to3 hook.
Port the minimal needed to get the test suite to run in python3.
Support reading packs from io.BytesIO

(io.BytesIO rasises a io.UnsupportedOperation when calling it's .fileno() method)
Skip tests in python3 that fail (most of them :-()
Enable testing python3.4 on travis.
Make a note in README that the Python3 port is ongoing.