av-forward: Stream webcam between a macOS host and a Linux guest

How to compile: 1. Run python ../tools/build.py process 2. Run python ../tools/build.py main

How to use: On the host: * You need ffmpeg installed . Run ./av-forward.

In the guest:
	* You need lsof, ffmpeg, pulseaudio, v4l2loopback-dkms, and v4l2loopback-utils installed.
	Run `sudo ./av-forward`.

That's it! The webcam will automatically turn off and on, depending on whether the guest is actively using it.

Known problems: * There is a slight (~0.5 s) delay between the host and guest streams. This is very small, but it seems to be unavoidable

* The quality of the stream in the guest is usable, but isn't great (ie, the guest can only access a compressed version of the stream natively available to the host)