Add Twitch IRC Support

[nyancrimew]

requirements appear to be setting the password and getting capabilities, twitch irc is documented quite well in their docs at https://dev.twitch.tv/docs/irc/authenticate-bot/

[Dpeta]

holy glubbing bingle,,

Twitch support would definitely be possible & silly, I've actually played around with it a bit before

[Dpeta]

Added a PASS field & twitch.tv/membership cap req with 14935a2 & da8e6dd, not actual proper support but seems to work given that:

• oauth pass scope has chat:edit+chat:read+whispers:read+whispers:edit
• nick/handle is identical to twitch name
• any channels joined are lowercase

[Dpeta]

Added an IRC compatibility option to stop Pesterchum from sending it's silly syntax & an option to force messages to have initials, so twitch!pchum/irc!pchum ought to be more usable now :3 (#120 + a7f266c)