add feature to warn staff of young accounts

[StealthySushie]

add a feature that can be set to ping staff of a server that an account is under a certain age when they join the server

[ThatRedKite]

I will add it to the pile

[aur0rae]

Unless there's any objection, I'll begin working on implimentation later this week or next. Should be a rather simple, low-cost check.