Add allow_overlapping_ips parameter to controller and neutron classes

Neutron puppet module was leaving the possibility to specify if
namespaces should be in use, while the openstack wrapper classes were
not.

Change-Id: I6f646e7c2e102adf90966b3d9b71f4f9fc0d8cd0
Merge "Add allow_overlapping_ips parameter to controller and neutron classes"