some minor fixes; From: Jan Stary

str is an optional argument to -t; if no argument is given, this
option is ignored (for compatibility reasons).

ok jmc@

add an EXIT STATUS section for /usr/bin;

add a description for -ztz

ok xsa@

convert to new .Dd format;

sync some manual page entries with actual usage.

ok jmc@, xsa@
mostly From: Igor Sobrado <igor at string1.ciencias.uniovi.es>

Make -n flag refer to -N flag instead of the other way around, since the
-N flag is above.

OK xsa@ and jmc@

a few bits about exit status here too; OK jmc@.

Clarify man pages to match -t behavior and pretty up usage strings.

OK xsa@ and jmc@.

remove the revision sections - it's explained in rcs(1) and i think
that's enough...

be consistent when describing revision selection;
input/ok: xsa joris niallo ray

keyword section is in rcs(1) now;

flesh out the description of ci; ok xsa

many spacing cleanups

wording fix from ray lai;
ok xsa

remove trailing whitespace;

`ci -k` is described incorrectly in a number of places.

- fix ci(1) manual page for this option
- fix usage() for this option
- fix CI_OPTSTRING for this option.

be consistent w/ `-tfile|str' documentation (cf. rcs.1);

- document `-t' option.

kill trailing whitespace;

- document `-i' and `-j' options, for which support was added a couple
of days ago.

document `-xsuffixes';

- fix up documentation for `-M' option.

- document `-s' option.

document TMPDIR env variable;