[Nickle]Union values

[Keith Packard]

Around 23 o'clock on Jul 26, Carl Worth wrote:

>  > 	u.i (10)
> 
> I'm not so sure. Now it looks like a "member function" for an object
> -- icky.

Ok, I'll bend.  Union values are in either:

	(type.name) value

or

	type.name

form.

> We must be doing something right then. Fun. :)

I could delete a lot more code if I used the least upper bound for type 
computations rather than a list of more specific types when dealing with 
poly.  I'm not sure I care about poly enough to have this complexity.

-keith