Swapping superclass from a module

[Emanuele D'Arrigo]

Wow, thank you all. Lots of ideas and things to try! I wish I knew
which one is going to work best. The module I'm trying to (monkey!)
patch is pxdom, and as it is a bit long (5700 lines of code.... in one
file!) I'm not quite sure if the simplest patching method will work or
the more complicated ones are necessary. Let me chew on it for a
little while. Luckilly pxdom has a test suite and I should be able to
find out quite quickly if a patch has broken something. Let me try and
chew on it, I'll report back.

Thank you all!

Manu