Split lines greater than 512 characters

[FugiTech]

600 a's in a PRIVMSG just get sent out as is. Probably shouldn't happen.

[FugiTech]

Fixed for PRIVMSG and NOTICE. MODE needs fixing (eventually), anything else?

[ElementalAlchemist]

When I get back to these, this needs a massive go-through of like every command in which input is sent back out.

[ElementalAlchemist]

I just realized this is still here.
The new code isn't in this repo, but we should make sure to audit the new 0.4 code for this. I believe this is handled for everything 0.4 could send, but we should verify.

Maybe @Heufneutje can help verify.

[Heufneutje]

I believe this is handled as well. The only commands that should really be affected by it in 0.4 are PRIVMSG/NOTICE (already fixed by @ElementalAlchemist), considering we're already preventing insane config values that could make lines with other commands too long.