adding MIDI stop control to Aeolus.
The protocol uses one controller number. The default is #98, but you can change this in global.h. The message is accepted only on channels enabled for control in the midi matrix.
The value is interpreted as follows:
v = 01mm0ggg
mm = mode. This can be: 00 disabled (initial value) 01 set off 10 set on 11 toggle
ggg = group, one of the button groups as defined in the instrument definition. In the GUI groups start at the top, the first one (for division III) being group #0.
The values of mm and ggg are stored and need not be repeated unless they change.
v = 000bbbbb
bbbbb = button index within the group.