For NetworkManager to properly take over a NFS-root system, we need to
have the interface name(s) in /tmp/net.ifaces and save the dhclient
lease. This lets the ifcfg module do its magic.
save_netinfo should properly write out /tmp/net.ifaces when needed, and
copies the dhclient files into place.
Add new functions: all_ifaces_up, get_netroot_ip, ip_is_local, ifdown,
setup_net, set_ifname, ibft_to_cmdline
Use them in netroot.sh and parse-ip-opts.sh.
There's also a couple little unrelated cleanups.
Harald Hoyer