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.tests/test/org/eclipse/birt/data/engine/olap/api/CubeFeaturesTest.java
41,42,43,44,45,
		46,47,48,49,50,
		51,52,53,54,55,
		56,57,58,59,60,
		61,62,63,65,65
    };
	
	static int[] ATTRIBUTE_Col = {
		1,2,3,4,5,
		1,2,3,4,5,
		1,2,3,4,5,
		1,2,3,4,5,
		1,2,3,4,5,
		1,2,3,4,5,
		1,2,3,4,5,
		1,2,3,4,5,
		1,2,3,4,5,
		1,2,3,4,5,
		1,2,3,4,5,
		1,2,3,4,5,
		1,2,3,4,5,
    };
	
	public void close( ) throws BirtException
	{
		
	}
	public int getFieldIndex( String name ) throws BirtException
	{
		if ( name.equals( "level11" ) )