Openbazaar python launcher

new pull request after 1st round of reviews.
Thanks @Renelvon this has the merged changes from your repo.

(@Renelvon I kept that REVERT commit you put there as I'm not sure I understood what was right or wrong about it, I figured it'd be easier to fix here now)
what kind of threading problems? is update_keywords_on_network being called from another thread? shared resources issues? locks?

I'm guessing perhaps this was added by someone to make saving contacts snappier in the UI.

We should probably have a limited thread pool to mitigate those.

If you don't mind I'll leave this fix outside of the scope of the python launcher PR.

This seems like it got here after rebases, we should address the threading as a separate issue.