Bug 121498 When datasource/dataset deleted, the datasource/dataset property binding element haven't been deleted
When deleted the datasource/dataset, the datasource/dataset property binding element haven't been deleted. Expected result: This operation must be a transaction.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ContentCommand.java
if ( !element.canContain( module, slotID, newElement ) )
			throw new ContentException(
					element,
					slotID,
					newElement,
					ContentException.DESIGN_EXCEPTION_INVALID_CONTEXT_CONTAINMENT );
		
		ContainerSlot slot = element.getSlot( slotID );
		if ( !slot.contains( oldElement ) )
			throw new ContentException( element, slotID, oldElement,
					ContentException.DESIGN_EXCEPTION_CONTENT_NOT_FOUND );
		
		if ( !oldElement.canTransformToTemplate( module ) )
			throw new ContentException(
					element,
					slotID,
					ContentException.DESIGN_EXCEPTION_TEMPLATE_TRANSFORM_FORBIDDEN );
		
		
		if ( hasDescendents( oldElement, slotID ) )
		{
			throw new ContentException( oldElement, slotID,
					ContentException.DESIGN_EXCEPTION_HAS_DESCENDENTS );
		}
		
		TemplateCommand cmd = new TemplateCommand( module, element );
		TemplateParameterDefinition templateParam = cmd.checkAdd( newElement,
				slotID );
		ContentRecord addTemplateParam = null;
		if ( templateParam != null )