Userland alarm: more complex test app
Userland alarm: more complex test app

Modify the multi-alarm test app to include delay_ms inside the alarm
callback. This makes sure the main alarm callback is re-entrant and also
seems to trigger a bug where the alarm stalls because a virtual alarm
expires before it is actually set...

tock/libtock-c,tock/libtock-c,tock/libtock-c