Changes for 2.0.16

• IE bugfix when dragging from a Diagram or Palette and dropping on a non-Diagram page element.
• Fixed the DraggingTool, when moving or copying between diagrams, to update the Diagram.currentCursor to be the Diagram.defaultCursor, not to "default".
• Fixed a bug when setting AnimationManager.isInitial to  false  when there are no Parts in the initial model.