Stopwatch Activity marks sorted by time per timer, even over multiple runs

[greenfeld]

Stopwatch-6 in OLPC OS 11.2.0 os14 attempts to sort all Marks recorded by time order. I'm not certain if this makes sense or not, since one currently cannot clear stored marks:

1. Start a timer. Wait 10 seconds, click the Mark button for that row.
2. Press the "Zero" button for that timer. Wait 5 seconds, take another mark.
3. Wait until 15 seconds in total have passed and press the Mark button again.

The result seen is you will have marks for approximately "5.00 10.00 15.00" in that order for that timer, even though the timer arguably has been run twice.