MFC r273627,r273628:

r273627:

  - Print out "Bail out!" in die(..) so prove terminates immediately
  - Handle the output from newer versions of openssl md5, similar to what
    pjd@ did in r248304

  Sponsored by: EMC / Isilon Storage Division

r273628:

  Move the redirection to stderr out of the cmd variable assignment

  Putting 2>/dev/null in cmd= escapes the redirection operation, which causes
  mdconfig to think it's a filename

  Sponsored by: EMC / Isilon Storage Division