gwrucio_registrar update time too aggressive
In rolling registration, the registrar daemon updates the time window from which it should register new files to start at the time of the last scan.
This is too aggressive: if files show up whose time stamp is less than the time of the last scan, they will be ignored. E.g. an initial scan run at t=5 could cover times [0, 10] while frames in that time period are still being produced. The next scan will occur at t=5.5 and cover times [5.5, 10], missing files in [0, 5.5].
Can we update registrar to set the minimum-gps to the most recently added frame, rather than the last scanned time?