Remove unused server-side /nick code

/nick is fully handled by the client without this code.
Remove unused server-side /rating etc. code
Don't join lobby if client asks not to
Locked users can PM auth
Fix Truant/flinch interaction
Rearrange formats, Glitchmons no longer ladderable
Gen IV: Fix Choice locking.

- Specifically, using Trick / Switcheroo while holding a Choice item and
receiving the same or a different Choice item keeps the user locked into
the move.
Gen IV: Fix Growth.
Gen 4: Fix crash in Curse
Muted users can speak in battles
Some mistake catching for lock feature
Crashfix for /loadbanlist
Modchat registered must be specified explicitly
Re-fix loadbanlist crash
/modchat on shouldn't change modchat settings
Malaconda Playtest ended
Eliminate the `crypto` variable in users.js
Check for sockets with empty `remoteAddress` (!)
Actually disconnect banned users
Don't accept `join` messages from banned users