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
*            <code>null</code>, then this element will no longer extend
	 *            another element.
	 * @throws ExtendsException
	 *             if the parent element is of the wrong type as this element.
	 */
	public void setExtends( DesignElementHandle parent )
			throws ExtendsException
	{
		ExtendsCommand cmd = new ExtendsCommand( module, getElement( ) );
		cmd.setExtendsElement( parent );
	}
	/**
	 * Sets the name of the element that this element extends. The name must
	 * resolve to an element of the same type as this element.
	 * 
	 * @param name
	 *            the name of the element that this one is to extend
	 * @throws ExtendsException
	 *             if no element exists with the given name, or if the element
	 *             is of the wrong type.
	 */
	public void setExtendsName( String name ) throws ExtendsException
	{
		DesignElement element = getElement( );
		ExtendsCommand cmd = new ExtendsCommand( module, element );
		cmd.setExtendsName( name );
	}
	/**
	 * Localize the element, break the parent/child relationship and set all the
	 * extended properties locally.