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)
There is a [section](https://github.com/OpenBazaar/OpenBazaar/wiki/Build-Instructions#pyelliptic) about that issue in the wiki. Maybe you could update it, too?