Bug 182895 Support sort on Level attribute.
Currently in OLAP engine we only support sort on level key value. We should go ahead to support sort on level attribute value.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/olap/data/api/CubeQueryExecutorHelper.java
if( value != null )
		{
			return (List)value;
		}
		List list = new ArrayList();
		dimJSFilterMap.put( dimensionName, list );
		return list;
	}
	
	/**
	 * 
	 * @return
	 * @throws DataException
	 * @throws IOException
	 */
	private IDiskArray[] getFilterResult( ) throws DataException, IOException
	{
		IDimension[] dimensions = cube.getDimesions( );
		IDiskArray[] dimPosition = new IDiskArray[dimensions.length];
		for ( int i = 0; i < dimPosition.length; i++ )
		{
			Dimension dimension = (Dimension) dimensions[i];
			List jsFilters = getDimensionJSFilterList( dimension.getName( ) );
			LevelFilterHelper filterHelper = new LevelFilterHelper( dimension,
					simpleLevelFilters,
					levelFilters );
			dimPosition[i] = filterHelper.getJSFilterResult( jsFilters, isBreakHierarchy );
		}
		return dimPosition;
	}