Bug 145022 Provide a utility method to help GUI enhance aggregate on.
DtE will provide a method hasAggregation(String expression) in org.eclipse.birt.core.data.ExpressionUtil, and the return value will be true when the expression is a valid JS expression and it has aggregation defined.
core/org.eclipse.birt.core/src/org/eclipse/birt/core/data/ExpressionUtil.java
* Return an IColumnBinding instance according to given oldExpression.
	 * 
	 * @param oldExpression
	 * @return
	 */
	public static IColumnBinding getColumnBinding( String oldExpression )
	{
		suffix++;
		return new ColumnBinding( PREFIX + suffix,
				ExpressionUtil.toNewExpression( oldExpression ) );
	}
	/**
	 * Translate the old expression with "row" as indicator to new expression
	 * using "dataSetRow" as indicator.
	 * 
	 * @param oldExpression
	 * @return
	 */
	public static String toNewExpression( String oldExpression )
	{
		if ( oldExpression == null )
			return null;
		char[] chars = oldExpression.toCharArray( );
		
		
		if ( chars.length < 5 )
			return oldExpression;
		else
		{
			ParseIndicator status = new ParseIndicator( 0,