nnimap support for "NAMESPACE" (prefix "INBOX." on courier-imap)

[Chris Shenton <chris@shenton.org>]

I'm "No Gnus v0.2" with a couple of courier-imap servers which use an
IMAP namespace of "INBOX.":

  * OK [CAPABILITY IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA IDLE NEWHORSE GRAPPA UMAMI LAPHROIG] Courier-IMAP ready. Copyright 1998-2003 Double Precision, Inc.  See COPYING for distribution information.
  2 login USERNAME PASSW0RD
  2 OK LOGIN Ok.
  3 namespace
  * NAMESPACE (("INBOX." ".")) NIL (("shared." "."))
  3 OK NAMESPACE completed.

Currently, when ever I want to refert to a server mailbox name (e.g.,
to move from my main inbox to some other) I have to use something like:

  nnimap+pectopah:INBOX.list.ding

Gnus defaults the part up to the colon, which is usally good, but I
have to type that INBOX. thing every time.   Is there a way to tell
Gnus to find out the namespace from the server and use this as a
prefix so I don't have to? 

  http://www.lysator.liu.se/~forsberg/docs/Gnus_and_Courier.xml

has some code which hides this display from the user, but IMHO that's
not the right thing -- gnus can figure out the prefix from the server.

Gnus *info* mentions "A note on namespaces" about mutant UoW IMAP
server behavior but doesn't say anything about setting one manually or
automatically.

Does Gnus have a way to determine this from the server? Have it
configured manually? use it when referring to mailbox names, for
retrieval, creation, moving, etc?

Thanks.