Update for degree.awk

Allow degree command to work the same as the change in deg, allowing modal key designations to be understood by the programs.  Example modal key designation would be *G:mix  for G mixolydian,  *d:dor for D dorian, *e:phr for E phrygian, *F:lyd for F lydian, *b:loc for B locrian.  Test to see if degree works with modal key:
    humcat h://370chorales/chor034.krn | degree -x