[IOS] Fix ios gesture end event not sent problem when gesture canceled

this pr include 2 commits:
1. Change to use gesture recognizer to handle single tap. this will fix the xbmc home button strange behavior after xbmc was backgrounded by 4 finger minimize gesture then came back. what caused the problem is: the 4 finger minimize gesture trigger the single touch begin event which send mouse left down event to xbmc, but after xbmc backgrounded and come back, no mouse up event sent to xbmc, which cause xbmc consider mouse is in pressed state, then the xbmc home button not react.
2. Handle gesture canceled notification and send gesture end event to xbmc. This fix the bottom screen buttons no reaction problem after xbmc was backgrounded by 4 finger minimize gesture or 4 finger swipe up gesture.