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.
A note can be placed in the center (panning=0) or moved to just the left
(panning=1) or right (panning=-1) channels. Fractional panning values
place it partially in both channels.
This class allows much more expressive sound synthesis:
* tremolo & vibrato
* arbitrary frequency
* different evelope & waveform per note
* all properties dynamically settable from Python code
This works for me (tested playing midi to raw files on host computer, as
well as a variant of the nunchuk instrument on pygamer)
it has to re-factor how/when MIDI reading occurs, because reasons.
endorse new test results
.. and allow `-1` to specify a note with no sustain (plucked)
In contrast to MidiTrack, this can be controlled from Python code,
turning notes on/off as desired.
Not tested on real HW yet, just the acceptance test based on checking
which notes it thinks are held internally.
