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
* When cube1 extends another cube2. Get access control from cube1.
	 * 
	 * <ul>
	 * <li>set permission
	 * <li>add role
	 * <li>remove role
	 * </ul>
	 * 
	 * will copies value access controls from the level of cube2 first. Then
	 * change the corresponding value. Undo is also tested.
	 * 
	 * @throws Exception
	 */
	public void testContentElementCommandOnLevel( ) throws Exception
	{
		openDesign( FILE_NAME_EXTENDS );
		
		TabularLevelHandle cube = (TabularLevelHandle) designHandle
				.findLevel( "testDimension/testLevel" ); 
		
		Iterator cubeAccess = cube.valueAccessControlsIterator( );
		ValueAccessControlHandle tmpAccess = (ValueAccessControlHandle) cubeAccess
				.next( );
		tmpAccess.setPermission( DesignChoiceConstants.ACCESS_PERMISSION_ALLOW );
		save( );
		assertTrue( compareFile( "TabularLevelAccessControl_golden_1.xml" ) );
		designHandle.getCommandStack( ).undo( );
		save( );
		assertTrue( compareFile( "TabularLevelAccessControl_golden_2.xml" ) );
		tmpAccess.addRole( "new 2nd role" );