Adds support for iOS6+ export and MMS group conversations

- iOS export needs real device testing and further analysis
- MMS group chat needs Android support still
Fix various bugs that keep the full script from running
Fix version bug
Fancier formatting / error / warning reporting

- optionally now requires 'blessings' library for color support
Fixes 'all messages unread' ios6 export bug, adds core and ios6 tests
Adds optional requirements and ups version
Change argument type to string, parser interface to use path

- All of this is to address issue #9
- support input json (sort of, needs testing)
Test related changes and fixes

- Updates json, csv, and xml parsers to pass tests.
- new base class for all tests to extend
- Ads 'runalltests.py' to run the entire test suite
Change Text() object to required named arguments
Fix google voice incoming/outgoing switch bug
Major fixes to iOS 6 parsing and writing

- Shouldn't fail on empty required fields, just warn
- makes a members field on each text for group texts
- adds more robust regression test for testing real files
Fixes android exception
Merge pull request #13 from t413/testing

Adds iOS message export support! First support for group chats.