Countdown with start button

Should be a way to record current time when start is pressed and run functions when certain buttons are pressed to get the difference in time between first recorded time and that time.

Start by locating the start-button handler and the existing functions called by the scouting buttons. Trace how event times are currently handled, then define the recorded start time and verify that each relevant button can calculate the elapsed time from it.

Written by the indexing model from the issue text.