Push 3 support - editing of velocity/response curve

[git-moss]

Comments from KVR:

"I had to change the MIDI names and Device ID just like you would have done in the Push 3 test version you shared. The only other thing I had to change was the frame header. Yours wasnt the same as the one in the Ableton github documentation or the python example I was using for my testing. So I changed that bit of your code to be the same as the Ableton documentations version of that frame header, and the display came alive."

"OK I went back and tried the standard frame header with the Push 2, and it makes the colours the same as what I was seeing on the Push 3. So I guess you had changed the ways colour worked by using a different frame header, and that frame header is not supported on the Push 3."