Bug 188052 Enhance the behavior of DimensionConditionHandle
Current in model implementation, there could be multiple DimensionConditionHandle corresponding to one dimension. This will cause problem for both UI and DtE. What we expect is that for each dimension, there are only one DimensionConditionHandle accompany with. Model should merge all the duplicate DimensionConditionHandle so that when UI/DtE is using model API the we can get unique DimensionConditionHandle for each dimension.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/parser/TabularCubeParserTest.java
* 
	 * <ul>
	 * <li>set permission
	 * <li>add role
	 * <li>remove role
	 * </ul>
	 * 
	 * will copies access controls from cube2 first. Then change the
	 * corresponding value. Undo is also tested.
	 * 
	 * @throws Exception
	 */
	public void testContentElementCommandOnCube( ) throws Exception
	{
		openDesign( FILE_NAME_EXTENDS );
		
		TabularCubeHandle cube = (TabularCubeHandle) designHandle
				.findCube( "testCube1" ); 
		
		Iterator cubeAccess = cube.accessControlsIterator( );
		AccessControlHandle tmpAccess = (AccessControlHandle) cubeAccess.next( );
		tmpAccess.setPermission( DesignChoiceConstants.ACCESS_PERMISSION_ALLOW );
		save( );
		assertTrue( compareFile( "TabularCubeAccessControl_golden_1.xml" ) ); 
		designHandle.getCommandStack( ).undo( );
		save( );
		assertTrue( compareFile( "TabularCubeAccessControl_golden_2.xml" ) ); 
		tmpAccess.addRole( "new 2nd role" ); 
		save( );
		assertTrue( compareFile( "TabularCubeAccessControl_golden_3.xml" ) );