Animating the drag view scale up and down when dragging items.

- Also fixing up how we draw the drag view alpha

Change-Id: Ied82aec9d52274b0fe65c989eab818b0264a9eb2

src/com/android/launcher2/DropTarget.java

@@ -55,6 +55,9 @@ public interface DropTarget {
         /** Indicates that the drag operation was cancelled */
         public boolean cancelled = false;
 
+        /** Defers removing the DragView from the DragLayer until after the drop animation. */
+        public boolean deferDragViewCleanupPostAnimation = true;
+
         public DragObject() {
         }
     }