Bug 189534 Computed Column aggregation builder doesn't accept argument.
The aggregation builder of computed column should be enhanced so that 1. It can accept aggregation argument. 2. Only when the selected computed column can accept argument should the argument dialog enabled.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/transform/pass/DataSetProcessUtil.java
}
	/**
	 * 
	 * @return
	 * @throws DataException
	 */
	private void populateComputedColumns( List aggCCList ) throws DataException
	{
		if ( !psController.needDoOperation( PassStatusController.DATA_SET_COMPUTED_COLUMN_POPULATING ) )
			return;
		
		if ( !psController.needDoOperation( PassStatusController.DATA_SET_FILTERING ) )
		{
			if ( iccState != null )
			{
				for ( int i = 0; i < iccState.getCount( ); i++ )
				{
					if ( iccState.isValueAvailable( i ) )
					{
						for ( int k = 0; k < this.populator.getQuery( )
								.getFetchEvents( )
								.size( ); k++ )
						{
							if ( this.populator.getQuery( )
									.getFetchEvents( )
									.get( k ) instanceof ComputedColumnHelper )
							{
								ComputedColumnHelper helper = (ComputedColumnHelper) this.populator.getQuery( )
										.getFetchEvents( )
										.get( k );