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/AggregationSortHelper.java
if ( CompareUtil.compare( values, key.getAxisQualifiers( )[i].getLevelValue( ) ) == 0 )
				{
					IAggregationResultRow temp = rSet.getCurrentRow( );
					diskArray[i].add( temp );
				}
			}
			for( int i = 0; i < result.length; i++ )
			{	
				result[i] = new AggregationResultRowNavigator( diskArray[i] );
			}
		}
		key.setFilteredResultSet( result );
	}
	static Object[] toObjArray( List l )
	{
		Object[] objs = new Object[l.size( )];
		for ( int i = 0; i < objs.length; i++ )
		{
			objs[i] = l.get( i );
		}
		return objs;
	}
	static boolean[] toDirectionArray( List sortKeys )
	{
		List result = new ArrayList( );
		for ( int i = 0; i < sortKeys.size( ); i++ )
		{
			SortKey sk = (SortKey) sortKeys.get( i );
			for ( int j = 0; j < sk.getAggrSortDirection( ).length; j++ )
			{