veyron/lib/netstate,netconfig: move netconfig out of the runtime and create netstate.
veyron/lib/netstate,netconfig: move netconfig out of the runtime and create netstate.

netstate is a set of routines for determining current networking state
and making policy based selections from the set of available addresses.

Change-Id: Iba2e20f046ae6018bd14f4fcb66f3d1c17af1518

vanadium/go.v23,vanadium/go.v23,vanadium/go.v23