Code cleanup

As a light exercise for a Sunday evening, I've made some code clean up involving mainly the removal of unused imports, stale looking code/comment parts, and some trivial PEP8 changes (adding/removing white spaces).

This PR builds on #47, since a significant amount of code was removed in that. Once that one is merged, I'll rebase this one to make the review easier.
@bsipocz - I think the above lines could be left - even though this is not used currently, it's good to have these here in case it's needed in future.