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
{
			return 0;
		}
		else if ( name.equals( "level12" ) )
		{
			return 1;
		}
		else if ( name.equals( "level13" ) )
		{
			return 2;
		}
		else if ( name.equals( "level21" ) )
		{
			return 3;
		}
		else if ( name.equals( "measure1" ) )
		{
			return 4;
		}
		return -1;
	}
	public int getFieldType( String name ) throws BirtException
	{
		if ( name.equals( "level11" ) )
		{
			return DataType.STRING_TYPE;
		}
		else if ( name.equals( "level12" ) )
		{
			return DataType.STRING_TYPE;