Switching to OpenNTPD

[Matthew Dillon]

    Ok, the Makefiles are all fixed up, plus I added the _pflogd and
    _ntp users and groups.   'make preupgrade' will update the password
    and group files, the standard 'upgrade' target will run preupgrade
    automatically, and 'make installworld' now prechecks all required groups
    and points out the new 'preupgrade' target to the user.

    I was able to slip the tags for 'make preupgrade', so that will work
    for everyone now (stable and HEAD users).  However, I couldn't slip
    the tag for installworld's prechecks due to other changes in HEAD
    for Makefile.inc1 so stable users will still get the old less informative
    message for the next 1-2 weeks.  Not a big deal.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>