Bug 182680 Use feature of new Aggregation framework of Data Engine.
DataEngine will implement new aggregation framework in 2.2.0RC0. After the implementation is finished Engine should go ahead to use new column bindings in definition of map/highlight.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/GetParameterDefinitionTask.java
ArrayList choices = new ArrayList( );
			while ( iter.hasNext( ) )
			{
				SelectionChoiceHandle choice = (SelectionChoiceHandle) iter
						.next( );
				String label = report
						.getMessage( choice.getLabelKey( ), locale );
				if ( label == null )
				{
					label = choice.getLabel( );
				}
				Object value = getStringValue( choice.getValue( ), dataType );
				choices.add( new SelectionChoice( label, value ) );
			}
			if ( !fixedOrder )
				Collections.sort( choices, new SelectionChoiceComparator(
						sortByLabel, parameter.getPattern( ),
						sortDirectionValue, ULocale.forLocale( locale ) ) );
			return choices;
		}
		return Collections.EMPTY_LIST;
	}
	private Collection getCascadingParameterList( ScalarParameterHandle parameter )
	{
		Object[] parameterValuesAhead =  getParameterValuesAhead( parameter );
		return getChoicesFromParameterGroup ( parameter, parameterValuesAhead );
	}
	/**
	 * convert the string to value.
	 *