Revert "Mouse: Changed mouseHandled check to a local var rather than …

…using originalEvent. Fixed #4333 - Nested draggables problem in IE"

This reverts commit 9c50bdf.

ui/jquery.ui.mouse.js

@@ -12,11 +12,6 @@
  */
 (function( $, undefined ) {
 
-var mouseHandled = false;
-$(document).mousedown(function(e) {
-	mouseHandled = false;
-});
-
 $.widget("ui.mouse", {
 	version: "@VERSION",
 	options: {
@@ -50,7 +45,9 @@ $.widget("ui.mouse", {
 
 	_mouseDown: function(event) {
 		// don't let more than one widget handle mouseStart
-		if(mouseHandled) {return};
+		// TODO: figure out why we have to use originalEvent
+		event.originalEvent = event.originalEvent || {};
+		if (event.originalEvent.mouseHandled) { return; }
 
 		// we may have missed mouseup (out of window)
 		(this._mouseStarted && this._mouseUp(event));
@@ -96,8 +93,7 @@ $.widget("ui.mouse", {
 			.bind('mouseup.'+this.widgetName, this._mouseUpDelegate);
 
 		event.preventDefault();
-
-		mouseHandled = true;
+		event.originalEvent.mouseHandled = true;
 		return true;
 	},