Dave instrument editor

the Dave instrument editor consists of these macros:

Volume: volume sequence.
Arpeggio: pitch sequence.
Noise Freq: set noise frequency source.
- 0: fixed frequency (~62.5KHz)
- 1: channel 1
- 2: channel 2
- 3: channel 3
Waveform: select waveform or noise length.
- 0: square
- 1: bass
- 2: buzz
- 3: reed
- 4: noise
- for noise channel the range is 0 to 3.
Panning (left): output level for left channel.
Panning (right): output level for right channel.
Pitch: fine pitch.
Phase Reset: trigger restart of waveform.
- does not apply for noise channel.
Control: set channel parameters.
- low pass (noise): enable low-pass filter. only in noise channel.
- swap counters (noise): enable swap counters mode. only in noise channel.
- ring mod: enable ring mod with channel+2.
- high pass: enable high-pass filter with the next channel.