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
I think that super render method could return a flag indicating if the element was rendered or not in order to setAppState. During drag&drop we could call to render just to transform it instead of creating any DOM element.