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
ContentException.DESIGN_EXCEPTION_CONTENT_NAME_REQUIRED );
		}
		
		ContainerSlot slot = element.getSlot( slotID );
		if ( !slot.contains( oldElement ) )
			throw new ContentException( element, slotID, oldElement,
					ContentException.DESIGN_EXCEPTION_CONTENT_NOT_FOUND );
		
		if ( oldElement instanceof TemplateElement )
		{
			if ( !oldElement.canDrop( )
					|| !oldElement.isTemplateParameterValue( module )
					|| !newElement.getDefn( ).isKindOf(
							( (TemplateElement) oldElement ).getDefaultElement(
									module ).getDefn( ) ) )
				throw new TemplateException(
						oldElement,
						TemplateException.DESIGN_EXCEPTION_REVERT_TO_TEMPLATE_FORBIDDEN );
		}
		else
		{
			if ( !oldElement.canTransformToTemplate( module )
					|| !( newElement instanceof TemplateElement ) )
				throw new ContentException(
						element,
						slotID,
						ContentException.DESIGN_EXCEPTION_TEMPLATE_TRANSFORM_FORBIDDEN );
		}