keys.quickOffset and keys.move stored the drag's new total before the
edit ran. When the edit refused the step (keys.quickOffset with a key
landing past the end of time), the project stayed as it was but the
total kept the refused delta, and with incremental steps (merge without
fromStart) the next step moved by it too.
The drag state is now stored only after the edit applies.
Test: a_refused_step_does_not_count_towards_the_drag (+1 s, a refused
step, -1 s: the keys end where they started; fails before: the last key
ends near the end of time).
tylerjenningsw
e1c9c33fb1