* Initial implementation of Program Up/Down and Tone Generator Up/Down selection and short cuts as buttons and MIDI buttons.
* Add configuration option for Program Change to act on Voices within a TG or Performances.
* Added PC option to Performance menu. Various bug fixes. Allow menu updating if on Performance/Load display. Swapped TG1 and TG3 in Performance 000008 so that TG1 is set to MIDI CH 1 in all Performances.
* Minor fixups in formatting and so on after review.
* Formatting fixups
* Changed config setting to match description in original manuals: Performance Select Channel. Also now accepts 1-16 or Omni as values.
* Additional fix to ensure GPIO buttons are working correctly on Voices or Performances.
* Changed initialisation order for PerformanceSelectChannel to avoid asset problem on a Pi 4 and updated menu text to fit nicely on a HD44780 display.