Issue #43: Bring python files into pep8 compliance

I've put everything except ecdsa into pep8 compliance,
changed a bunch of DOS newlines (\r\n) into unix newlines (\n).

The ecdsa looks like it's from another library so I left that as is.
Merge pull request #44 from jimmysong/43

Issue #43: Bring python files into pep8 compliance