Commands:

:r -- register via Register(email)

:u -- change username via UserUpdate

:d [n] [file] -- dump backlog of last 'n' msgs to a file 'file'

Features:

* remove JSON config

* read $home/lib/discord.face for profile picture (or just face?)

* delete disco.cfg on failure to log in for 400 bad request: password does not match

* ensure proper permissions -rw------- 0600 for discord.cfg

* if ``` entered, allow multi-line message (composition)

* replace <:emoji:3lk4j12:> garbage with :emoji:

* clean up @'s

* replace libnotify shenanigans, add a goroutine to check for pings

* flag for larger backlog loading