Allow provider network overlapping ips and namespaces

Previously, when provider networks were selected,
overlapping ips and namespaces were set to false.

The dhcp service should still be able to allow
overlapping ip addresses and to use namespaces, so
these settings have been updated.
Update vlan default configuration

This commit updates the default vlan config in hiera.

disables ovs tunneling, and ensures that bridge
mappings are still set to reasonable defaults.