Here are the variants of the wristwatch.

   - "w"  means watch
   - "s1" means stopwatch 1 (the original one, in file "stopwatch1.strl")
   - "s2" means stopwatch 2 (the one that forgets about LAP mode, in file
                             "stopwatch2.strl")
   - "s"  means any stopwatch
   - "a"  means alarm

For example, "button-ws1a.strl" is the button interpreter for watch,
stopwatch 1, and alarm, while "display-ws.strl" is the display handler
for watch and stopwatch (the display doesn't care about which stopwatch
is there) .

To build a variant, e.g. the "ws2a" wristwatch, just type

   make wristwatch-ws2a.c


