A hold-tap timer event would be triggered too soon if the hold-tap
was delayed for longer than its tapping-term. This may cause
accidental hold behavior when the correct behavior would be tap.
By queuing the timer event instead of executing it immediately,
other delayed events get a chance to be processed properly.
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.
Peter Johanson