Bug 145021 Enhance the agrregate on option in column binding dialog
1. Check if the expression is aggregate expression by data utility class. 2. If yes, the option is ?all? and group name list 3. if not, the option disabled (or set to none?) if the column binding is in detail row. If the column binding is in group row, the option is ?None? and group name list.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/dnd/InsertInLayoutUtil.java
handle = ( (ListBandProxy) target ).getElemtHandle( );
		}
		if ( handle instanceof GroupHandle )
		{
			return (GroupHandle) handle;
		}
		return null;
	}
	/**
	 * Inserts invalid column string into the target. Add label if possible
	 * 
	 * @param expression
	 *            invalid column or other expression
	 * @param target
	 *            insert target like cell or ListBandProxy
	 * @return to be inserted data item
	 * @throws SemanticException
	 */
	protected static DesignElementHandle performInsertString(
			String expression, Object target ) throws SemanticException
	{
		
		
		
		
		DataItemHandle dataHandle = DesignElementFactory.getInstance( )
				.newDataItem( null );
		dataHandle.setValueExpr( expression );
		InsertInLayoutRule rule = new LabelAddRule( target );
		if ( rule.canInsert( ) )