[Cython] Results of XPathTransform / W3CDOM experiments

[Dag Sverre Seljebotn]

> xpath way of going about it is cleaner. Also, I don't see the end
> user as writing their own transformations much (nor do I think it's a
> good idea to encourage it--it makes the language much more obscure).

This was definitely considered a feature to help with developing Cython,
if transforms made a coding-style convenient where each change could be
described in relative isolation in one function.

But I'll definitely stick it in the drawer. Fun experiment though. I
should have known that finally having a legitimate use for Python
metaclasses was too good to be true... ;-)

Dag Sverre