Bug 142928 Item from library is changed to a report design item after revert to report item
Details: Item from library is changed to a report design item after revert to report item. Setp: 1.New a template. 2.Use a libary contain a label. 3.Drop the label from library explorer into layout. 4.Change the label to template item. 5.Revert the template item to report item. Actual result: The label is become a report item, but a item from library. Please see the attach image. Exception result: The lable is revert a item from library.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/DesignElementHandle.java
*            position in the slot that the child item will be added.
	 * @throws ContentException
	 *             if the element is not allowed in the slot
	 * @throws NameException
	 *             if the element has a duplicate or illegal name
	 * 
	 */
	public void addElement( DesignElementHandle child, int slotId, int pos )
			throws ContentException, NameException
	{
		SlotHandle slotHandle = getSlot( slotId );
		if ( slotHandle != null )
			slotHandle.add( child, pos );
	}
	/**
	 * Adds a report item to the end of the given slot. The item must be newly
	 * created and not yet added to the design.
	 * 
	 * @param child
	 *            handle to the newly created element
	 * @param slotId
	 *            slot id in which the child item will be added.
	 * @throws ContentException
	 *             if the element is not allowed in the slot
	 * @throws NameException
	 *             if the element has a duplicate or illegal name
	 * 
	 */
	public void addElement( DesignElementHandle child, int slotId )
			throws ContentException, NameException