Bug 1023950 - Implement real state handling for mozApps and apply visual...

 - gaia-confirm now has a JS + DOM Event API (I updated the example)
 - mozApp states are now handled entirely by gaia-grid which means l10n changes (moved to shared) many additional tests and some nicer code (which depends on bug 1027458)
- visuals for app states
The fact that this hashchange triggers a this.destroy as a direct consequence of handleEvent is not very clear.

Can you just add a switch/case for hashchange, that does nothing but just say in a comment that the prompt needs to be destroyed on a hashchange and move the this.destroy() call of handleEvent at the end.