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
Explain it a bit more. Why does the hash is changed when the home button is pressed ? (I know it, but i will be good to explain that in the comment, and so explain why the confirm dialog needs to be removed.