Pure python launcher now equivalent to run.sh.

Just needs --config parameter to accept a configuration file on startup and I'll submit this
as a pull request to develop branch.

Will also need to merge latest changes after this point, to make sure this will be easy to merge
with latest changes on master.

 - Supports development mode, launchers multiple instances, makes sure every instance has db setup. refactors.
 - configure.sh: make sure to use env/bin python tools, small refactor.
 - requirements.txt: fixed pystun requirement
 - openbazaar (posix CLI launcher) makes sure openssl library is in DYLD_LIBRARY_PATH if running on macosx.

 Fixes on transport.py:
 - commented out inet_pton calls. inet_pton wasn't actually
 doing anything except raise exceptions. in the event that
 inet_pton would actually work, its output was not being used
 to obtain the ip in raw network format anyways.
 - now when we shutdown transport, we make sure the zmq event
 stream is closed properly.
 - in case the market_id is different after we load the settings
 we make sure the OpenbazaarContext object knows is updated.
 - ipv4.icanhazip.com fix on periodic callback updater (fixed merged from master branch)