Reported device state may not be correct

[danesparza]

If the appliance monitor is stopped while the appliance is still running and then started again while it's not running, /system/state will report that it's running (even though it's not).

On startup, we need to sanity check the most recent /activity and probably ensure that it's set to not running.

[danesparza]

If it's currently running, and the most recent activity was 'started', and the activity was within 3 hours - don't log a new 'started' activity. Just use the old one.