Foreign groups and server parameters.

[Jan Vroonhof <vroonhof@math.ethz.ch>]

Currently Gnus considers the server parameters to be part of the
"server name" , IMHO this is a bad idea:

Suppose you have created a server in the server buffer with parameters
other than "nil" and you subscribe to a few groups from it. Gnus will
save the parameters along with the group discription.

Now suppose you want to change the parameters (say because
nntp-open-server-function has changed its name). Now all your old
groups still have the old set of parameters. This will cause an
automagically created new server with these paramters to appear and
the paramters change won't work.
I see no other possibility than to 1. edit nntp.eld directly or 2.
kill the groups and resubscribe them.

I think gnus-open-server should:

look if there is a server with the same name (possibly compare backend
too), if so use it's parameters. If not, create a new one with the
parameters saved with the group.

Jan