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
false,
						this.session );
			AggregationHelper helper = new AggregationHelper( new AggrDefnManager( aggrInfos ),
					this.populator );
			AggrComputedColumnHelper ccHelper = new AggrComputedColumnHelper( helper,
					aggrNames );
			this.populator.getQuery( ).getFetchEvents( ).add( 0, ccHelper );
			PassUtil.pass( populator,
					new OdiResultSetWrapper( populator.getResultIterator( ) ),
					false,
					this.session );
			this.populator.getQuery( ).getFetchEvents( ).remove( 0 );
		}
		finally
		{
			Context.exit( );
		}
	}
	/**
	 * 
	 * @throws DataException
	 */
	private void doDataSetFilter( boolean changeMaxRows ) throws DataException
	{
		if(	!psController.needDoOperation( PassStatusController.DATA_SET_FILTERING ))
			return;
				
		
		applyFilters( FilterByRow.DATASET_FILTER,
				changeMaxRows );