Added downloading speed and lift range.  Fixed some errors around vector rescaling.  Added "upload speed" and "upload lift range" as buttons, but upload speed isn't showing up for some reason.  Another day.  Removed procontroll as a dependency and the gamepad as an input device.  Commented out code in case anyone else wants it.
Merge branch 'webcam' of https://github.com/euphy/polargraphcontroller into webcam