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/util/sort/DimensionSortEvalHelper.java
/**
	 * 
	 */
	public Object evaluate( IResultRow resultRow ) throws DataException
	{
		super.setData( resultRow );
		Context cx = Context.enter( );
		try
		{
			return ScriptEvalUtil.evalExpr( expr, cx, scope, null, 0 );
		}
		catch ( IJSObjectPopulator.InMatchDimensionIndicator e )
		{
			return null;
		}
		catch ( BirtException e )
		{
			throw DataException.wrap( e );
		}
		finally
		{
			Context.exit( );
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.data.engine.olap.util.sort.IJSSortHelper#getSortDefinition()
	 */
	public ISortDefinition getSortDefinition( )