[arch-general] netcfg2: background running

[gan lu]

Do your great devs plan to add support of  background running capability
(adding @ like in the rc.conf daemon section) for netcfg2 (net-profile), I
have set a ethernet-static and adsl internet connection when booting up, but
if adsl got some trouble to connect, which makes my computer waiting for it
like ages. Thanks.