Bug 153040 Template definition should be removed after the report item is deleted
Steps to reproduce: 1.New a report, extends lib.label 2.Convert the label to template report item, and revert it back to the report item 3.Delete the label 4.Remove the included library Expected result: Library can be removed Actual result: A BIRT exception occurred. Plug-in Provider:Eclipse.org Plug-in Name:BIRT Model Plug-in ID:org.eclipse.birt.report.model Version:2.1.0.v20060808-0630 Error Code:Error.LibraryException.LIBRARY_HAS_DESCENDENTS Error Message:The library "Lib" can no be dropped because it has descendents "NewLabel" in the current module.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ContentCommand.java
* @param toSlotID
	 *            the slot within the new container.
	 * @param newPos
	 *            the position in the target slot to which the content will be
	 *            moved. If it is -1 or greater than the size of the target
	 *            slot, the content will be appended at the end of the slot.
	 * @throws ContentException
	 *             if the content cannot be moved to new container.
	 */
	private void doMove( DesignElement content, int fromSlotID,
			DesignElement to, int toSlotID, int newPos )
			throws ContentException
	{
		assert content != null;
		assert to != null;
		assert newPos >= -1;
		
		if ( element == to && fromSlotID == toSlotID )
			return;
		
		
		if ( content.isVirtualElement( ) || content.getExtendsName( ) != null )
			throw new ContentException(
					element,
					fromSlotID,
					content,
					ContentException.DESIGN_EXCEPTION_STRUCTURE_CHANGE_FORBIDDEN );
		
		if ( to.isContentOf( content ) )
			throw new ContentException( to, fromSlotID, content,