Restart debouncing timers after every event

Closes #616 (closed)

A timer restart is all this needs, right? A walk in the park compared to the tapping state machine I'm usually working with.

Restarting the timers has the effect of allowing infinitely long bouncing sequences, but that needs an equally long string of input events with alternating up / down button state, each within the timeout of the previous one, so that shouldn't be a problem, I think.