Fixing issues with spring loaded adding.

- Delaying until items are added
- Showing bg when going into spring loaded mode
- Fixing regression where dropping widgets on full page would not trigger a notification
- Fixing regression on tablet where pages were no longer being rotated or shown

Change-Id: Iadc0c406f0c065c5029addea1abfee395eed81b9

src/com/android/launcher2/DropTarget.java

@@ -49,6 +49,9 @@ public interface DropTarget {
         /** Where the drag originated */
         public DragSource dragSource = null;
 
+        /** Post drag animation runnable */
+        public Runnable postAnimationRunnable = null;
+
         public DragObject() {
         }
     }