Clean up the ifdef maze in usage() by reformatting it to have distinct

Clean up the ifdef maze in usage() by reformatting it to have distinct
!SMALL and SMALL sections.  This makes future changes easier to review
and to compare with the man page's synopsis.

The usage output is the same as before so there is no change from the
user's point of view.

usage() cleanup and !SMALL/SMALL separation suggested by jmc@
ok jmc@