Bug 189706 Enhance computed column aggregation function handling in UI.
Due to the issue discussed in 189705, current computed column aggregation builder in data set editor has bugs to extend: 1.When new a computed column, the aggregation argument field cannot be correctly set. 2.The argument field cannot be correct grayed out when user select a aggregation function without arguments 3.The available aggregation function list is incomprehensive 4.Some aggregation function cannot be set to model(say, weightedAve).
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/transform/pass/DataSetProcessUtil.java
*/
	private DataSetProcessUtil( ResultSetPopulator populator,
			ComputedColumnsState iccState,
			ComputedColumnHelper computedColumnHelper,
			FilterByRow filterByRow,
			PassStatusController psController,
			DataEngineSession session)
	{
		super( populator,
				iccState,
				computedColumnHelper,
				filterByRow,
				psController, session);
	}
	
	/**
	 * Populate the data set data of an IResultIterator instance.
	 * 
	 * @param populator
	 * @param iccState
	 * @param computedColumnHelper
	 * @param filterByRow
	 * @param psController
	 * @throws DataException
	 */
	public static void doPopulate( ResultSetPopulator populator, ComputedColumnsState iccState,
			ComputedColumnHelper computedColumnHelper, FilterByRow filterByRow,
			PassStatusController psController, DataEngineSession session ) throws DataException
	{
		DataSetProcessUtil instance = new DataSetProcessUtil( populator,