Supports loading config flags from file, other suggested fixes.

- supports --config-file <file> option.
- cyrpto_util has no os specific code. Mac's DYLD_LIBRARY_PATH check moved to openbazaar_daemon.py
- suggested fixes on comments.
- fixes import issue on test_transport.py

Still to do:
 `$ openbazaar stop`
 `$ openbazaar status`
post merge pep8 fixes, cleanup
openbazaar stop [WIP]
run.sh and stop.sh no longer needed
Fixes and refactors as suggested by @Renelvon

 - dropped bitmessage, web_xxx (only http used now)
 - removed bitmessage flags and related code.
 - flag settings cleanup & refactors.
next round of refactors and fixes.

 - moved default context values inside OpenBazaarContext.get_defaults()
 - new OpenBazaarContext.create_default_instance(), used now on test_transport.py -> get_mock_open_bazaar_context()
 - imports cleanup
 - '--database' is no more, now it's self explanatory and unambiguous '--db-path'
 - When shutting down we now have a mutex to make sure two SIGTERM and SIGKILL don't call the application.shutdown() routine at the same time.
 - style fixes.
multiple refactors (encapsulation, readability, modularity, pep8)

should fix test breakage

Stopping from the Web UI was broken.
bring back bitmessage and attempt to connect it

pep8

brought back bitmessage

make connect_to_bitmessage() parametric again

missing parameters