shift states only affect associated buttons

ONLY WORKING FOR BUTTONS NOT POVs CURRENTLY

= If none of the active shift states apply to a button, that button will
be in the default state.
So if button 1 has shift states for "default" and "mode1", but shift
mode mode2 is active...
...the button will be in the "default" state as "mode2" is not
associated with button 1.