morebits: Fix the fix

Embarrassing!
batchdelete: Allow single-request deletions

Still takes two requests for the deletion of redirects, as we want to know
whether they are protected.

Got rid of most of the XPath (#226), but there is still a little bit left
in the unlinking code.

Also got rid of the disputed CSD stuff. This was killed from other modules
ages ago (except delimages), as it is a legacy from when {{hangon}} was
widely used.

Also in morebits, do what the comment says.