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)
No need to have two long switches with the same function. Drop `--my-market-port` and patch `openbazaar_daemon` as needed.