Key/Oct improvements

• Added a failsafe where if you send above MIDI note 127 (G9), only G9 will be sent instead of wrapping around to send note number 0
  • MAX will also be shown on the OLED to show that you have exceeded the MIDI note numbers
• Doubled the default pad pitch bending to roughly 2 semitones
  • Currently the full pitch bend isn't a full 2 semi tones due to an issue where multiplying by a decimal result in instability, will fix this later but sounds close enough in my opinion
• Rewrote the change key/oct menu so that the controller can be used whilst in these settings.
  • Before if you wanted to hear the difference you would have had to exit the settings
  • I would advise against changing the key/oct whilst you are playing a note to prevent instability, but from my testing the controller can manage it
• Some minor optimisations to the OLED code