We have code to enable and disable the RTC's UIE interrupt, as well as
check whether it occurred and skip the first interrupt as it may be
bogus.
This is currently used as part of maintaining the correction file.
In a later commit, we will need the same functionality for using the RTC
as reference clock, so export the functions and give them descriptive
names appropriate for globally visible functions.
This is useful on computers that have an RTC, but there is no battery to
keep the time when they are turned off and start with the same time on
each boot.
This is a verbatim copy of the files at that stage of the repository that was
built from the CVS import. It allows future development to see a bit of recent
history, but without carrying around the baggage going back to 1997. If that
is really required, git grafts can be used.
