find(1): Sync with FreeBSD
Originally I did this to gain the -quit feature. It turns out that we
already had it, but FreeBSD didn't document it until 4 years after they
implemented it, so it wasn't on our man page either.
With this sync, we get time comparisons down to the nanosecond. We get
the -sparse option. The behavior of -delete was changed the delete the
files given as arguments.
The only thing that was omitted with all the birthtime options.
The new find was used successfully in locate.update job, something
that failed in the last sync and code in functions.c had to be
partially reverted.