Bug 154828 Item from library contant user properties can't delete
Details: Item from library contant user properties can't delete Step: 1.New a library. 2.Add a label and add a user properites. 3.Public the library. 4.New a report design and use the library 5.Drop the label from library explorer into layout. 6.Try to delete it. Actual result: The label from library contant user properties can't be delete. Exception reuslt: The label can be delete.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ContentCommand.java
if ( hasDescendents( oldElement, slotID ) )
		{
			throw new ContentException( oldElement, slotID,
					ContentException.DESIGN_EXCEPTION_HAS_DESCENDENTS );
		}
		
		ContentReplaceRecord replaceRecord = new TemplateTransformRecord(
				module, element, slotID, oldElement, newElement );
		ActivityStack stack = getActivityStack( );
		stack.startFilterEventTrans( replaceRecord.getLabel( ) );
		try
		{
			doDelectAction( oldElement, unresolveReference );
			
			TemplateCommand cmd = new TemplateCommand( module, element );
			cmd.checkAdd( newElement, slotID );
			
			stack.execute( replaceRecord );
			addElementNames( newElement );
		}
		catch ( ContentException e )
		{
			stack.rollback( );
			throw e;
		}
		catch ( NameException e )
		{
			stack.rollback( );
			throw e;
		}