Bug 1092904 - [Stingray] Implement the config object

* Add a config object.

Conflicts:
	tv_apps/browser/js/mediator.js
Yes, thanks @rexboy7 ! The comments were added below.

@evelynhung from the discussion with @rexboy7 and John, instead of loading a config JSON file at run time, we're planning to make config as a javascript object which is generated at build time. The generated config could still be lazy loaded at run time when needed.