[IRCServices] Feature: nickchange and guestnickprefix

[Alexander_Zverev at oxy.com]

> Andrew isnt refering to 'randomly generated nick 
> registration', Andy is just stating that the nickname that 
> services will change your nick to is 'randomly generated' 
> what and is also saying, that if it were to generate a new 
> nickname for a user based on its current nickname, it would 
> have to check to see if that nickname is registered before 
> changing it. (for example, Craig is taken, someone tries to 
> use it, Services wants to change the nickname to Craig132123, 
> it has to check to see if Craig132123 is already registered 
> before changing the nickname. Otherwise, you may hit another 
> already registered nick.). Nicknames with the guestprefix 
> cannot be registered at all. Meaning that services doesnt 
> have to perform registration checks on it before changing the nick.

This situstion are very highly unlikely, isn`t? 
Improve randomization, add one more check, that`s it.
Anyway, services ask password again.


PS:
This feature alredy implemended on some services and I don`t see any
problem there.