Porting PagedView from KG to gain simplified scaling model, reordering

-> We are no longer scaling individual Celllayouts, instead we are scaling
   the entire Workspace (and the CellLayouts come along for the ride)
-> Due to the above change, many assumptions were broken. In particular,
   our drag and drop / animation archiecture is fairly fragile due to the
   frequent and complex mapping of points between different bits of the
   hierarchy. This CL contains a number of fixes which address such
   breakages.

Change-Id: I2e630eab17528729b764b61f587858f6499fd318

src/com/android/launcher3/ButtonDropTarget.java

@@ -112,7 +112,7 @@ public class ButtonDropTarget extends TextView implements DropTarget, DragContro
     }
 
     @Override
-    public void getHitRect(android.graphics.Rect outRect) {
+    public void getHitRectRelativeToDragLayer(android.graphics.Rect outRect) {
         super.getHitRect(outRect);
         outRect.bottom += mBottomDragPadding;
     }
@@ -155,11 +155,6 @@ public class ButtonDropTarget extends TextView implements DropTarget, DragContro
         return to;
     }
 
-    @Override
-    public DropTarget getDropTargetDelegate(DragObject d) {
-        return null;
-    }
-
     public void getLocationInDragLayer(int[] loc) {
         mLauncher.getDragLayer().getLocationInDragLayer(this, loc);
     }