venus-setup decides when to call coda-setup-ports by omitting the call
on debian.  It should omit it on NetBSD also, and perhaps in general,
and we should add systems on which to run it; systems without coda in
/etc/services are in 2005 deficient.

Also, since this is a shared venus/vice thing, perhaps the check on
whether to do anything belongs in the coda-setup-ports script itself.

Thoughts, Jan?  I can send a patch, but only want to do that in the
direction you are willing to take.

This seems to be one of those files that is installed for both client
and server.