test(1) scans for "operators" linearly in an array using strcmp() to
find a match. Since the list of "operators" is fixed, split them
into one and two character ones, and ones that start with a `-' and
ones they don't. This way we can optimize the compare function to
just check for one or two characters. Sort and use bsearch(3). We
could have used a single sorted array and bsearch(3), to save some
complexity, but I decided to be a bit fancier.