Thumb detection/rejection suffers from an uncecessary minimum finger movement speed threshold
With the latest thumb rejection branch that was just merged, I see an issue:
When I place just my index finger on the pad, move it slowly, and then drop my thumb, the pointer stops moving and it becomes an unwanted two-finger scroll gesture. Recording: Doesn_t_work_because_index_finger_is_moving_slowly.txt
When I do the same thing but move my index finder more quickly before dropping the thumb, the thumb is correctly ignored. Recording: Works_because_index_finger_is_moving_somewhat_quickly.txt