Enable vlan networking for newer neutron plugin
Enable vlan networking for newer neutron plugin

Ironic's CI makes extensive use of VLAN based networking
and the newer neutron plugin hardcodes the tenant networking
type to vxlan which is naturally problematic. It also lacks the
ability to set the necessary constraints for vlan networking
which are added for vxlan networking.

This patch enables the type of tenant networking to be defined
as vlan, and enables for a physical network vlan range mapping
setting to be configured which is required for a vlan to be
allocated upon network creation.

Change-Id: I55874c1ce82898e9dfb81505d8f3b14abde33579

openstack-dev/devstack,nawawi/openstack,openstack-dev/devstack,dtroyer/devstack,dtroyer/devstack,nawawi/openstack