Re-introducing an app event for apps to do cleanup

Until Appcelerator fixes app-events not being cleared on restart, apps needs to know when restart happens so they can clean up:

```
if (!ENV_PRODUCTION && Ti.Shadow) {
	Ti.App.addEventListener('tishadow:close', function() {
		Ti.App.removeEventListener('resumed', onResume);
	});
}
```
Merge branch 'patch-16' of github.com:FokkeZB/TiShadow into FokkeZB-patch-16

Conflicts:
	app/Resources/api/TiShadow.js