Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
Convert 1000000 usec to 1 sec 0 usec.
Use provided safe malloc (rtmalloc()) instead of malloc(): exit on allocation
failure.
Correct use of .Nm
Add usage() and use errx().
