Add some root features (Quick uninstall, Clear cache)

It should all work now. Though the icon for 'Clear cache' still needs to be done. I quickly added one for hdpi but I guess you'll find some better ones in your collection ;)

By the way, currently you are always launching a new activity (ClickHandlingActivity) when doing something in the widget. But I think an Activity isn't needed there at all (you're either launching a new Activity, or you are doing the root magic) so I guess the use of a 'ClickHandlingService' is a cleaner solution.