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.report.data.adapter/src/org/eclipse/birt/report/data/adapter/api/DataAdapterUtil.java
{
	/**
	 * This method is used to register the Java Script Objects which are defined in the scope of
	 * source ResultSet ( might be IResultSet or CubeCursor ) to target scope. One possible client
	 * of this method is Report Engine. A classic use case is that instead of register its own "row" object 
	 * the Report Engine can simply call this method with proper argument so that the "row" object
	 * registered in IResultIterator's scope, that is, JSResultSetRow, can be accessed by engine using
	 * engine scope. 
	 *   
	 * @param targetScope
	 * @param source
	 */
	public static void registerJSObject( Scriptable targetScope,
			ILinkedResult source )
	{
		int type = ( (ILinkedResult) source ).getCurrentResultType( );
		if ( type == ILinkedResult.TYPE_TABLE )
		{
			targetScope.put( "row", targetScope, new JSResultIteratorObject(
					(ILinkedResult) source ) );
		}
		else if ( type == ILinkedResult.TYPE_CUBE )
		{