The 'networks_lower' group_var carries a mapping of
network.name to network.name_lower for all networks.
The external_bridge interface on DVR compute nodes
that do not have the 'External' network associated
with the role still need to be able to lookup the
name_lower for the 'External' network.
The lookup via role_networks_lower fail's since the
'External' network is'nt associated.
Also if the 'External' network is associated with the
role set the address and routes.
For the mutliple_nic_vlans add address and routes and
the vlan member interface on the bridge.
Note, also remove duplicate name entry on the 'Tenant'