Message and documentation cleanups

Message and documentation cleanups

* Update version number in INSTALL and mention where we do most of
srvx's testing.

* Move the message about using the authcookie to inside of
nickserv_make_cookie(), so that when another cookie exists, only the
"cookie already pending" message is sent.

* Fix various typos, extraneous sentences, and misplaced command
listings in nickserv.help.

* Remove (unused) fakehost options from srvx.conf.example and update
ChanServ's set_shows option.
git-archimport-id: srvx@srvx.net--2004-srvx/srvx--devo--1.3--patch-33