this makes LS(LEFT_CONTROL) work as if shift and control were both
pressed explicitly. Previously, the left shift would have been released
as soon as another key was pressed. The implicit behavior is useful in
case of LS(NUMBER_1) when rolling over to other keys.
Also see #361.
* Add timestamps to position events and behaviors.
- Take original event timestamps into consideration so nested tap-holds have proper timing.
- Add position and timestamp to keycode state changed event so the one-shot behavior can properly identify other keypresses and timings.
- Add timestamp to position events received from peripheral
* reduce number of arguments to behaviors
