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/expression/ExpressionProcessor.java
*/
	public void setQuery( BaseQuery query )
	{
		this.baseQuery = query;
	}
	
	/*
	 * @see org.eclipse.birt.data.engine.executor.transform.IExpressionProcessor#setResultIterator(org.eclipse.birt.data.engine.odi.IResultIterator)
	 */
	public void setResultIterator( IResultIterator resultIterator )
	{
		this.resultIterator = resultIterator;
		
		dataset.setResultSet( this.resultIterator, false );
	}
	/*
	 * @see org.eclipse.birt.data.engine.executor.transform.IExpressionProcessor#clear()
	 */
	public void clear( )
	{
		if ( availableAggrList != null )
			availableAggrList.clear( );
		availableAggrList = null;
	}
}
/**
 * 
 * 
 */
class ExpressionInfo