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
Instead of the switch/case can't you simply:

handleEvent: function(event) {
  this.setAppState(this._determineState(this.app));

 if (event.type === 'downloadapplied') {
   this.renderIcon();
 }
}