do it's job it would have to choose between two cases:
1. either it would take a very long time to get the correct adjustment, thus,
if you are not currently on the net right, you wait a long time (or must
type ^C, which is ridiculous)
2. ntpd could be modified to "abort early", but then would not meet the
promise made by -s in the manual page (note: it does not say that it
"tries")
therefore, -s and -S must become user choices.  Sorry.  This same choice is
made in lots of other places

once at startup. ntpd delays daemonizing until it has done the intial
time setting (or ran into the timeout) in this mode to make sure stuff started
later in rc is not subject to time jumps.
this eleminates the need to run rdate -n beforehands.
with some input from & ok ryan and bob, march music from mickey

mostly from Andreas Kahari (PR #3846);