Replaced error message for channel mode +M with ERR_NEEDREGGEDNICK_MSG
(used by Bahamut, inspircd, ircu & Unreal too) and using numeric 477
and the msg simliar like inspircd.
Replaced the error message ERR_CANNOTSENDTONICK_MSG for user mode +b
with ERR_NONONREG_MSG and using numeric 486, similar like unrealircd.
(cherry picked from commit 55a61ab17f63a9e757b7c7598c31b98ce5a132e8
and commit 3737d9ab7da1ea0485cefc07c65dc5308bf0db02)