More improvements to encoding handling. There is now a server encoding that

More improvements to encoding handling. There is now a server encoding that
is independent from the message sending/receiving encodings, so you can have a
channelname encoded in ISO, for example, and still send messages in utf8 to that
chan.
No UI to configure this yet, the server encoding is hardcoded to Latin1 for now. The
rest can be edited in network settings.