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
DimensionHandle dimension = (DimensionHandle) propHandle.getContent( 0 );
		assertEquals( dimension, cube.getContent(
				TabularCubeHandle.DIMENSIONS_PROP, 0 ) );
		assertEquals( "testDimension", dimension.getName( ) ); 
		assertTrue( dimension.isTimeType( ) );
		propHandle = dimension
				.getPropertyHandle( DimensionHandle.HIERARCHIES_PROP );
		assertEquals( 1, propHandle.getContentCount( ) );
		assertEquals( 1, dimension
				.getContentCount( DimensionHandle.HIERARCHIES_PROP ) );
		
		TabularHierarchyHandle hierarchy = (TabularHierarchyHandle) propHandle
				.getContent( 0 );
		assertEquals( hierarchy, dimension.getContent(
				DimensionHandle.HIERARCHIES_PROP, 0 ) );
		
		assertEquals( hierarchy, dimension.getDefaultHierarchy( ) );
		assertEquals( "testHierarchy", hierarchy.getName( ) ); 
		assertEquals(
				designHandle.findDataSet( "secondDataSet" ), hierarchy.getDataSet( ) ); 
		
		iter1 = hierarchy.accessControlsIterator( );
		accessControl = (AccessControlHandle) iter1.next( );
		assertEquals( "hierarchy user1; hierarchy user2", accessControl 
				.getPropertyHandle( IAccessControlModel.USER_NAMES_PROP )
				.getStringValue( ) );
		assertEquals( "hierarchy role1; hierarchy role2", accessControl 
				.getPropertyHandle( IAccessControlModel.ROLES_PROP )
				.getStringValue( ) );