TouchScroll: expose number of active touches as _touches for extensions

TouchScroll.js

@@ -502,10 +502,10 @@ function(declare, on, has, put){
 	}
 
 	function incrementTouchCount(evt){
-		touches[evt.widget.id] += evt.changedTouches.length;
+		evt.widget._touches = touches[evt.widget.id] += evt.changedTouches.length;
 	}
 	function decrementTouchCount(evt){
-		touches[evt.widget.id] -= evt.changedTouches.length;
+		evt.widget._touches = touches[evt.widget.id] -= evt.changedTouches.length;
 	}
 
 	return declare([], {
@@ -530,6 +530,12 @@ function(declare, on, has, put){
 		//		(i.e. bouncing back from beyond edges) should take.
 		bounceDuration: 300,
 
+		// _touches: Number
+		//		Reports number of touches currently in contact with this widget.
+		//		Mostly used internally for determining when to scroll, but may also
+		//		be useful info for further extensions.
+		_touches: 0,
+
 		startup: function(){
 			if(!this._started){
 				this._initTouch();