* stage 3:
+ Check whether it works properly with hot plugged network
interfaces. That is, stage 3 should not assume that these
interfaces come up at any particular time but should wait
for networking to become available.
+ Determine whether the primary interface is 16-bit PCMCIA,
cardbus, or neither. Then,
1. If PCMCIA, mark the interface neither "auto" nor "hotplug"
2. If cardbus, mark the interface "hotplug"
3. If neither, mark the interface "auto"
The current code doesn't do this IIUC.
 This means, of course, listing the interface name on a "map"
line in the "mapping hotplug" stanza.