[IRCServices Coding] TS3/4 Support

[Chris Plant]

Hello

I'm working on monkeyircd's protocol module for services, and I've hit a
problem.
As I understand it, in TS3 mode, when services loses its link/shuts
down, it should send/receive QUITs for all the clients it handles.  But
in TS4 mode it just receives a SQUIT for the link lost, and then should
calculate the QUITs and SQUITs that follow as a consequence.

How hard would it be to change the protocol module to either of these
behaviours (I suspect the former would be easier).  MonkeyIRCD handles
both behaviours, as specified in the TS4 protocol, by using either
TS3/TS4 as declared at the start of a server link session.

Chris