RFC: blow Ethernet-over-USB into a module

[Werner Almesberger]

Andy Green wrote:
> This patch stops making Ethernet-over-USB as a built-in and makes it a
> module instead.  If you use NFS like that you will hate it.

Hmm, I understand the goal. Unfortunately, this also means that having
bad modules can now prevent you from ssh'ing in even more easily :-(

I just wish USB had ports, just like TCP does, or devices had hardware
that lets one emulate hubs ...

- Werner