spindles can now give us detailed logs for start and end of steps. the appview can ingest these logs to indicate live durations for steps. it is implemented like so: - the logs handler keeps track of start and end times for each step - whenever we recieve a start or end time, we update the html to add a `data-start` or `data-end` attribute - using some javascript, we print a live updating timer for each step: * if only `data-start` is present: then use Now - Start and update each second * if both `data-start` and `data-end` are present, then use End - Start Signed-off-by: oppiliappan <me@oppi.li>