cleaned up isListening API. introduced new enableHitGraph config that can be used to disable the hit graph

test/unit/DragAndDrop-test.js

@@ -24,6 +24,13 @@ suite('DragAndDrop', function() {
         //change properties
         circle.setDraggable(true);
 
+
+        //circle.on('click', function(){});
+
+        layer.draw();
+
+        showHit(layer);
+
         // test new properties
         assert.equal(circle.getDraggable(), true);
     });