command to include explicit mention of the -o opt and +o opt forms.
Fix the synopsis to have the 4 forms that the description of the
utility discusses, rather than expecting users to understand that
the 3rd and 4th forms of the command were combined into the 3rd
synopsis format. After doing that, the options in the 3rd format
no longer need to be optional, so now all 4 formats are distinct
(previously, the third, omitting everything that was optional, and
the first, could not be distinguished).
While here, some wording and formatting "improvements" as well (nothing
too serious).
4c31efd22f