degesch: almost multiserver

degesch: almost multiserver

I’ve been writing degesch with the multiserver ability in mind and I’m making good progress on reaching that goal.

After today’s commits, all that remains is adding a /server command to manage the servers and changing the configuration format to allow specifying multiple servers by name. Actually I’m not so sure how to act on server removal at the moment, so that might delay things up a bit.

All buffers now have the server name as a prefix. For the time being, it’s always the default server name, "server".