Add control values

[gamblor21]

Added in common control change values as per #10

I used a couple of reference list, this is not exhaustive. But seems to be the more popular ones.

[ladyada]

@kevinjwalters please try it!

[tannewt]

@jedgarpark probably knows if these are relevant CC values too.

[kevinjwalters]

The new Continue message works based on pressing play, play, stop in Ableton lite.

Press any key to enter the REPL. Use CTRL-D to reload.
Adafruit CircuitPython 5.3.1 on 2020-07-13; Adafruit CircuitPlayground Express with samd21g18
>>> import adafruit_midi
>>> import usb_midi
>>> import time
>>> from adafruit_midi.start import Start
>>> from adafruit_midi.stop import Stop
>>> from adafruit_midi.timing_clock import TimingClock
>>> from adafruit_midi.control_change import ControlChange
>>> from adafruit_midi.midi_continue import Continue  ### new one
>>> midi = adafruit_midi.MIDI(midi_in=usb_midi.ports[0], in_channel=0)
>>> while True:
...     msg = midi.receive()
...     if msg is not None:
...         print(time.monotonic(), msg)
...
...
...
10558.6 <MIDIUnknownEvent object at 20003f70>
10558.6 <Start object at 20004120>
10558.6 <TimingClock object at 20004300>
10558.6 <TimingClock object at 200018d0>
10558.6 <TimingClock object at 20002470>
10558.6 <TimingClock object at 20002d70>
10558.7 <TimingClock object at 200034e0>
10558.7 <TimingClock object at 20003aa0>
10558.7 <TimingClock object at 20004420>
10558.7 <TimingClock object at 20001c60>
10558.7 <TimingClock object at 200026f0>
10558.8 <TimingClock object at 20002f80>
10558.8 <TimingClock object at 200039f0>
10558.8 <TimingClock object at 200041e0>
10558.8 <TimingClock object at 200017b0>
10558.8 <TimingClock object at 20002260>
10558.9 <TimingClock object at 20002bb0>
10558.9 <TimingClock object at 20003320>
10558.9 <TimingClock object at 20003c40>
10558.9 <TimingClock object at 200042e0>
10558.9 <Stop object at 20001720>
10558.9 <MIDIUnknownEvent object at 20001850>
10558.9 <Continue object at 20001c70>
10559.0 <TimingClock object at 20002630>
10559.0 <TimingClock object at 200027e0>
10559.0 <TimingClock object at 20002d70>
10559.0 <TimingClock object at 20003590>
10559.0 <TimingClock object at 20003b60>
10559.1 <TimingClock object at 20004690>
10559.1 <TimingClock object at 20001e70>
10559.1 <TimingClock object at 20002960>
10559.1 <TimingClock object at 200030a0>
10559.1 <TimingClock object at 20003690>
10559.1 <TimingClock object at 20003d60>
10559.2 <TimingClock object at 20004520>
10559.2 <TimingClock object at 20001ec0>
10559.2 <TimingClock object at 20002750>
10559.2 <TimingClock object at 20003220>
10559.3 <TimingClock object at 20003790>
10559.3 <TimingClock object at 200040b0>
10559.3 <TimingClock object at 20001720>
10559.3 <TimingClock object at 200024f0>
10559.3 <TimingClock object at 20002fc0>
10559.4 <TimingClock object at 20003750>
10559.4 <TimingClock object at 20003e20>
10559.4 <TimingClock object at 20004640>
10559.4 <TimingClock object at 20002050>
10559.4 <TimingClock object at 20002ad0>
10559.5 <TimingClock object at 20003270>
10559.5 <TimingClock object at 20003cc0>
10559.5 <Stop object at 20004010>

[kevinjwalters]

The CC numbers look fine and work, here's global volume and mod wheel on my Axiom 25 going to CPX:

Press any key to enter the REPL. Use CTRL-D to reload.
Adafruit CircuitPython 5.3.1 on 2020-07-13; Adafruit CircuitPlayground Express with samd21g18
>>>
>>> import adafruit_midi
>>> import usb_midi
>>> import time
>>> from adafruit_midi.control_change import ControlChange
>>> from adafruit_midi.control_change_values import *
>>> midi = adafruit_midi.MIDI(midi_in=usb_midi.ports[0], in_channel=0)
>>> while True:
...     msg = midi.receive()
...     if isinstance(msg, ControlChange):
...         if msg.control == MOD_WHEEL:
...             print("MOD_WHEEL", msg.value)
...         elif msg.control == VOLUME:
...             print("VOLUME", msg.value)
...
...
...
VOLUME 9
VOLUME 19
VOLUME 28
VOLUME 35
VOLUME 39
VOLUME 40
VOLUME 35
VOLUME 26
VOLUME 18
VOLUME 9
VOLUME 0
MOD_WHEEL 79
MOD_WHEEL 76
MOD_WHEEL 72
MOD_WHEEL 65
MOD_WHEEL 56
MOD_WHEEL 44
MOD_WHEEL 29
MOD_WHEEL 15
MOD_WHEEL 0