Added :i for import js component.
Please put js components under `b2g_js/js_component/` folder.
Added "-c system" and "-c -1" for System App.
Updated README.
Refactoring runner.py.
Added :l & :o commands into b2g_js.
 :l - List all apps of b2g instance.
 :o <KEYWORD> - Connect to the App iframe. Using # ID or App_URL as <KEYWORD>.
Added error handling.
Merge pull request #3 from askeing/master

Sync