Libvirt driver to use current nova.network.model

* Updated tests to use VIF class instead of legacy "network,mapping" tuple.
* Modified libvirt/{driver,firewall,vif}.py to use VIF class instead of legacy
  "network,mapping" tuple.

Change-Id: Ic67291f3bfa7624af38061fa61a88ff16aa5acda
Fixes: bug 1112646
Merge branch 'bug-ipv6-libvirt' into bug-ipv6-step3

Conflicts:
	nova/virt/libvirt/vif.py

Change-Id: I87f17dc3d0b588c780efef677b6c7ee05a7021df
get_injected_network_template to use the current network model

Change-Id: Id74e02b70e2eaa4dd53b66fe10eb6263cade6df1
Fixes: bug 1112659