restrict nicknames of common services?

[12:13:24 PM] Koragg: not sure if you wish to limit MemoServ BotServ Global and OperServ as nicks as well or not (there seems to be no numeric to verify a network service)

Inspircd appears to use `310 RPL_WHOISSERVICE` to identify services, but this is conflicted; `313 RPL_WHOISOPERATOR` (used by Unreal) seems like a solid compromise).