Showing all folders from disconnected or paused remote devices as
unaccepted would be a lot of false positives. As we cannot know
whether the remote has accepted while it doesn't have an active
connection, let's better report false negatives, as in assuming the
folders are accepted.
This truncates times meant for API consumption to second precision,
where fractions won't typically matter or add any value. Exception to
this is timestamps on logs and events, and of course I'm not touching
things like file metadata.
I'm not 100% certain this is an exhaustive change, but it's the things I
found by grepping and following the breadcrumbs from lib/api...
I also considered general-but-ugly solutions, like having the API
serializer itself do reflection magic or even regexps on returned
objects, but decided against it because aurgh...
Adds a new folder state "Waiting to Sync" in the same vein as the
existing "Waiting to Scan". This vastly improves performances in the
rare cases when there are lots and lots of folders operating.
