WobbyHW/DDS.py docstrings, skeleton main(), API renames

Signed-off-by: Gray Remlin <gryrmln@gmail.com>
rpi_voltmeter.py & rpi_signalgen.py API updates

Signed-off-by: Gray Remlin <gryrmln@gmail.com>
rpi_wobbulator.py fileencoding=ascii

Signed-off-by: Gray Remlin <gryrmln@gmail.com>
TODO updates

Signed-off-by: Gray Remlin <gryrmln@gmail.com>