Discovered a problem with nextbus_fetcher running on a remote
server: the timezone was UTC, not US/Eastern, so the timestamps
were off by 5 hours.  Sigh.  Simple short term solution is
to just prefix the command with TZ=US/Eastern.  Longer term
I'll be adding a flag to allow the TZ to be specified for the
archivers.
Added support in util/time.go for time.Location flags, and some
tests, which revealed the need for improvements in compare.DeepCompare
to provide formatting of differences.