required merging ud-ldap and ud-ldap-cgi from Debian

This is to follow our template, but it also clarifies the distinction
between the different stages

During the textile/fsn-node-03 replacement, there were disk problems
that were not detected until right about the time I was ready to go to
production. It would have been nice to automatically find those
instead.

The rationale here is we don't want to extend trust from the old
machine, which we do by giving them root access on the new server. By
giving root access to the *old* server, we don't give it access to
anything it already has (or will have, in the case of the ganeti
nodes).

While this procedure is available in a billion places already, this is
the kind of stuff that you mess up when you get awaken at 3AM and can
barely type.

Let's see if we can get the human error out of the equation a little
more by helping those poor infected water bags a little.