Bug 188578 Add "displayColumnName" on TabularLevel
Add Property "displayColumnName" on TabbularLevel and corresponding APIs on handle. Property Type: expression.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/parser/TabularCubeParserTest.java
valueAccess.addValue( "new value 1" ); 
		level.add( ILevelModel.VALUE_ACCESS_CONTROLS_PROP, valueAccess );
		save( );
		assertTrue( compareFile( "TabularCubeParserTest_extends_golden_3.xml" ) ); 
		valueAccess
				.setPermission( DesignChoiceConstants.ACCESS_PERMISSION_ALLOW );
	}
	/**
	 * Notification should be only sent to cube if access control/value access
	 * controls are changed. It should be only one PROPERTY event.
	 * 
	 * <ul>
	 * <li>for local value change.
	 * <li>for extends case.
	 * </ul>
	 * 
	 * @throws Exception
	 */
	public void testNotification( ) throws Exception
	{
		openDesign( "CubeParserTest_2.xml" ); 
		
		TabularCubeHandle cube = (TabularCubeHandle) designHandle
				.findCube( "testCube" ); 
		MyListener listener = new MyListener( );
		cube.addListener( listener );
		PropertyHandle propHandle = cube
				.getPropertyHandle( TabularCubeHandle.ACCESS_CONTROLS_PROP );
		
		AccessControlHandle accessControl = designHandle.getElementFactory( )