Using a pool.ntp.org server seems nicer and more open-source-y,
but until our pool use is approved, let's put in a default value
that works.
(time.google.com serves smeared time instead of doing leap seconds.
pool.ntp.org doesn't serve smeared time. I intend to implement
client-side leap second smearing since nobody likes jumpy timestamps.
For now, we get this for free.)
This only queries a single NTP server, only does a point-to-point
request, doens't do any filtering, doesn't display the response
in any useful format, and is generally very bare-bones.
But maybe, over time it can learn to query more servers, do
filtering, run as a service that keeps state over time to
improve filtering, adjust system time, and maybe learn to
run as an NTP server then.
