Update NEWS and ChangeLog files
Streamline punctuation of log messages

See commit d38d153f for details.
Fix return code of some IRC_WriteXXX() functions

These functions usually write to more than one target, and therefore
can't return value indicating success or failure in a sane way. And, even
more omportant, these functions should send to as much as possible clients
and not stop at the first client which isn't reachable any more!
irc-write.c: Clean up code and add more documentation comments
irc-macros.h: Update copyright, don't forget contributors!
Introduce new function IRC_WriteErrClient()

This function is used to send "error messages", including numerics,
back to clients and to automatically enforce a 2 second penalty. With
this patch, all error results enforces a delay for the client.

All callers of IRC_WriteStrClient(ERR_xxx) have been converted.

Please note that this patch prolongs the time "make check" needs
to complete its tests, because of lots of new enforced penalties ...
IRC_SERVER(): Code cleanup