may fail some tests, yet conform to standard too; for non-stable sort,
quite a few tests have actually more possible 'correct' results, yuck!
check for presence of -S and use it to switch to non-stable sort - the tests
are not written for stable sort
Fix test 37 - for 'sort -m -r' to actually work, the input files have
to be reverse sorted as well. Now the in-tree BSD sort passes this test ;-)
print the used sort command and parameters for 'failed' messages
other small sleanups, remove accidentaly added debug stuff
put it comment that this was derived from stuff written by
Peter McIlroy - it's not clear now that it's separate from
the rest of new BSD-licenced sort(1)
