Kill off the static single net device and move to proper dynamic
registration (which we need with the new device model).

Break the (flawed) assumption that all network-layer protocols can use
ARP; such network-layer protocols (i.e. IPv4) must now register as an ARP
protocol using ARP_NET_PROTOCOL() and provide a single method for checking
the existence of a local network-layer address.

point trying to use the old boot sequence.  Replaced with a call to the
AoE demo code, so that people can at least build and try something useful.

portions such as the stack) during the installation process.

init_fns() are called from main().  We need to think about initial
control flow some more.

Use %m to print error

initial device, and will also allow for e.g. a device menu to be presented
to the user.

link time to accommodate whatever bus objects are included.

the boot device.

*other* than the main boot device.

out the new probing logic.

call it initialise() and place it in main.c.  :)