Act as Ethernet gadget over USB

[jywarren]

https://www.hardill.me.uk/wordpress/2017/01/23/raspberry-pi-zero-gadgets/ has great docs for this that don't require bonjour/zeroconf!

[jywarren]

This also allows it to become a usb disk!

[jywarren]

https://www.hardill.me.uk/wordpress/2017/02/12/updated-pi-zero-gadgets/