Support ML2 vlan driver

Provides additional parameters required for configuring the vlan ml2
driver.  Parameters are exposed from the base Neutron classes.

Sample Hiera data:

openstack::neutron_tunneling: false
openstack::neutron_type_drivers: ['vlan']
openstack::neutron_tenant_network_type: ['vlan']
openstack::neutron_tunnel_id_ranges: []
openstack::neutron_bridge_uplinks: ['br-ex:bond1']
openstack::neutron_bridge_mappings: ['default:br-ex']
openstack::neutron_network_vlan_ranges: ['default:80:80']
Use include-style declarations for common classes

Classes that are used commonly outside this module should be included
where possible to avoid duplicate declaration errors.  Many sites
will have their own base profiles that already define ntp and
firewall rules.
Merge branch 'vlans'