Mouse: Reset click event suppression on next mousedown. Fixes #6946 -…

… Mouse: click event suppressed after drag in Gecko(cherry picked from commit 548bdb1)

ui/jquery.ui.mouse.js

@@ -75,6 +75,11 @@ $.widget("ui.mouse", {
 			}
 		}
 
+		// Click event may never have fired (Gecko & Opera)
+		if (true === $.data(event.target, this.widgetName + '.preventClickEvent')) {
+			$.removeData(event.target, this.widgetName + '.preventClickEvent');
+		}
+
 		// these delegates are required to keep context
 		this._mouseMoveDelegate = function(event) {
 			return self._mouseMove(event);