strlcpy.3: Use OpenBSD's revamped description of strlcpy and strlcat.

This is FreeBSD's r257646.

Submitted-by: Eitan Adler <eadler@freebsd.org>

From their commit msg:

This explanation is supposed to be simpler and better.  In particular
"comparing it to the snprintf API provides lots of value, since it raises the
bar on understanding, so that programmers/auditors will a better job calling
all 3 of these functions."
mdoc_local: Add two more FreeBSD versions which are used in manual pages.
hammer2 - Stabilization

* Do not scrap deleted + modified chains unconditionally, this will mess
  up operations on unlinked-but-open files.  Also fixes an assertion which
  was getting hit and fixes poudriere test run stdout EBADF errors on
  unlinked fifos.

* Optimize handling of the DESTROYED flag to restore the feature where a
  rm -rf can get away with doing almost no write I/O.

* Remove a bunch of debug stuff