Now available: arguments.callee

There is now arguments.callee available in XWT CVS.

This allows one time traps to disable themselves cleanly, and for 
anonymous functions to be recursive.

Your 'one time only' traps should no look like this:

> SizeChange +=  = function() {
>     normal = true;
>     SizeChange -= arguments.callee;
> }

Another feather in Nitrogen's fairly hefty cap.

- Charlie