Composition: Vertical Slit Scan

Vertical slit scan implementation in Vuo. Inspired in part by Paul (@pbourke)'s work here: https://vuo.org/node/2005. Uses a bunch of layers. I can run at least 720 slits (which are layers(!)) on my '15 MBP, but as it is an old machine it will probably work faster/better on newer models. I have only tested with the built in camera on the macbook, which limits the speed/resolution of it. If anyone has a 60fps camera and the machine to run it on, I'd love to see some results at higher resolutions and speeds!