ScopeChain is inspected when looking up variable

To improve the debugging experience when using nested functions.

Allows the variables heightOfFormItemHeader and item to be inspected from within the nested function.

```actionscript
private function getFormItemResizeFunction(item:FormItem):Function
{
	const heightOfFormItemHeader:int = 40;
	return function (height:Number):void {
		item.height = height + heightOfFormItemHeader;
	};
}
```