fallback for nss and stuff in libc

[ibotty <bsd@xxxxxxxxxx>]

this is out for discussion.

when we have our nss+auth daemon (how to name that beast?),
we will have stubs in libc to message that daemon.

when this daemon is not available, we should try to start it (this should
only happen in single-user mode, though).

if that fails, how are we going to deal with it?

because, it will be impossible (ehem, should be impossible), that the daemon
cannot be started by root or crashes, we would NOT need any fallback.

in the case, that it does not start (due to a bad kernel or daemon), it
should be at least possible to mount a cdrom and cp a know working kernel
and daemon.
so IMO, the only fallback needed is to support mount and cp.

~ibotty