Semi-incompatible name change: The method `release_then_press`
is now `change`. For now a compatibility alias is supported.
Everywhere a `NoteSequence` was accepted, a single note is now accepted.
So for instance, `synth.press(30)` can be written instead of requiring
``synth.press((30,))`. The same goes for `change.retrigger`, which
will accept a single LFO or a sequence.