* Clean up whitespace in qa/ in preparation for .editorconfig. Convert tabs to 4 spaces. Indent by 4 spaces. Strip trailing whitespace. Ensure EOL at EOF.
Use sine wave instead of sawtooth because it is
easier to hear glitches.
Add some options:
-a - Test ALL devices, otherwise just the default devices.
-i - Test INPUT only.
-o - Test OUTPUT only.