were pointed out by Brooks Davis and Alexey Dokuchaev:
* It now tries to lookup arguments as names first, then tries
to parse them as numbers. In particular, this makes the
behavior consistent with POSIX conventions when usernames
consist entirely of digits.
* It now uses strtoul() for the numeric parsing.
Finally, I've included an update to the test harness
to exercise the new numeric cases for -R.
Approved by: re (kib)