ChanServ seen fixes; other cleanups

ChanServ seen fixes; other cleanups

* Remove rule to generate the unused EXTRA_MODULES preprocessor macro.

* Properly adjust ChanServ seen time when a user leaves or is kicked
from a channel.

* Read languages from disk before initializing the core services,
since they must all be available when loading accounts.

* Fix a typo in the log BNF documentation, and add =SEVLIT support for
consistency.

* Add missing "invalid" to NSMSG_INVALID_ANNOUNCE string.
git-archimport-id: srvx@srvx.net--2004-srvx/srvx--devo--1.3--patch-29