Changes for xen vif routing, also a couple of new rules for elabinelab (multicast, apod).
Changes for xen vif routing, also a couple of new rules
for elabinelab (multicast, apod).

nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome