Set vibrato waveform

Tracker 4.44

### 14-4 Set vibrato waveform

Acceptable range is 0-3: 0 is the default sine, 1 the square, and 2 the rampdown. Protracker docs speak of 3 being a random waveform, but I've yet to see it implemented ! Neither pt1-1, pt1-2 nor pt2-0 implement it. You're supposed to add 4 to control whether the viboffset is reset at each note (if 4, not reset, but this looks buggy as hell to me...) See Vibrato, for the waveforms used.

Scrolling mode:

         1 A-4 vb mode

with `mode` being one of `sine, sqre, ramp` or `SINE, SQRE, RAMP` if the viboffset should not be reset.