webcam basically works, but only webcam. no video file option (commented that all out). will need to do more work/cleanup on the webcam version before merging webcam and video file versions
VideoSource is a container that can hold either a video or a webcam, and can be used like either
switching to a video file from webcam works, but only after the webcam has loaded. need to figure out how to smoothly handle switching back and forth, and which one to start with.
neither webcam nor file is default; switching between them is smoother now
added saveframes option back in
cleanup, added some documentation