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/api/DesignElementHandle.java
DesignElementHandle targetHandle ) throws SemanticException
	{
		assert ( targetHandle.getModule( ) == getModule( ) );
		if ( targetHandle.getModule( ) != getModule( ) )
			throw new IllegalArgumentException(
					"The target element should be in the same report !" ); 
		if ( targetHandle.getDefn( ) != getDefn( ) )
			throw new PropertyValueException(
					targetHandle.getDefn( ).getName( ),
					PropertyValueException.DESIGN_EXCEPTION_WRONG_ELEMENT_TYPE,
					PropertyType.ELEMENT_REF_TYPE );
		PropertyDefn propDefn = (ElementPropertyDefn) getDefn( ).getProperty(
				propName );
		if ( propDefn == null )
			throw new PropertyNameException( getElement( ), propName );
		propDefn = (ElementPropertyDefn) targetHandle.getDefn( ).getProperty(
				propName );
		if ( propDefn == null )
			throw new PropertyNameException( targetHandle.getElement( ),
					propName );
		Object value = getElement( ).getLocalProperty( module,
				propDefn.getName( ) );
		if ( value == null )
		{
			targetHandle.setProperty( propName, null );
			return;
		}
		if ( DesignElement.NAME_PROP.equals( propName )
				|| DesignElement.EXTENDS_PROP.equals( propName ) )
		{