getChangedTouches=function(event){
      if(angular.isDefined(event.changedTouches)){
        return event.changedTouches;
      }else{
        return event.originalEvent.changedTouches;
      }
    }
Returns event.changedTouches directly if event is a TouchEvent.
If event is a jQuery event, return changedTouches of event.originalEvent