Adds doc2ps (in /rc/bin) and antiword (in /bin/aux) to
doc2txt(1).

Noticed several misspellings from the distrib version; this
also fixes them. Fixed outdated URL in SEE ALSO. Ordered
the options table for msexceltables alphabetically.

Pedantics: changed usage() in msexceltables.c,
mswordstrings.c and olefs.c to match.