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/impl/aggregation/sort/AggrSortDefinition.java
private String aggrName;
	private DimLevel[] axisQualifierLevel;
	private Object[] axisQualifierValue;
	private DimLevel targetLevel;
	private boolean direction;
	private static Logger logger = Logger.getLogger( AggrSortDefinition.class.getName( ) );
	
	/**
	 * 
	 * @param aggrLevels
	 * @param aggrName
	 * @param axisQualifierLevel
	 * @param axisQualifierValue
	 * @param targetLevel
	 * @param direction
	 * @throws DataException 
	 */
	public AggrSortDefinition( DimLevel[] aggrLevels, String aggrName,
			DimLevel[] axisQualifierLevel, Object[] axisQualifierValue,
			DimLevel targetLevel, boolean direction ) throws DataException
	{
		Object[] params = {
				aggrLevels,
				aggrName,
				axisQualifierLevel,
				axisQualifierValue,
				targetLevel,
				new Boolean( direction )
		};
		logger.entering( AggrSortDefinition.class.getName( ),