macOS utility for sharing Goggles v1/v2 on laptops

This adds `usb2sock`. It does the job of translating the video stream from
the usb cable to a network connection such as what vlc can display.

See instructions in usb2sock.c: download libusb, build it, compile
the usb2sock.c file into a standalone command-line binary, run it,
open VLC and Open Networking, paste this MRL: tcp/h264://127.0.0.1:18080

Then plug in the goggles.

Author: davidhubbard