BareMetal driver to use current nova.network.model

* Updated tests to use classes from nova.network.model instead of legacy
  "network,mapping" tuple.
* Modified baremetal/{driver,pxe,vif_driver}.py to use classes from
  nova.network.model instead of legacy "network,mapping" tuple.

Change-Id: I8b4efa4bfb804c658b29d80373d9d0e4572b8e20
Fixes: bug 1112642
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-baremetal' into bug-ipv6-step1
Merge branch 'bug-ipv6-libvirt' into bug-ipv6-step1