UTF-8 support

As of the next reboot...

MUME now has partial support for UTF-8, meaning that you can connect with a
client that uses the UTF-8 character encoding instead of Latin-1 (ISO 8859-1)
to type accented letters and such.

You're still restricted to using the characters defined in Latin-1, but you can
use the UTF-8 encoding.

MUME will auto-detect input to be either UTF-8 or Latin-1, but you can change
output using "change encoding utf-8" (that's the new name for the old "change
charset" command).

- Dáin