This adds a new "allow_forceset_usermodes" attribute to protocol modules, which determines whether the IRCd allows us to force usermode changes on other servers' clients.
Also, make sure our target is a valid nick/UID/channel, and that the parsed modes are not empty!
- admin: Drop "showchan" command. It's not very useful, and doesn't handle long output strings at all.
- All the remaining commands are dedicated to spawning bots and playing with them anyways, so this new name fits better.