Incoming cloud config for OpenStack is complex due to plugins and
deployer choices. Rather than having the logic spread all over the
OpenStack modules, centralize it in the module_utils code.
Taking a page out of the ec2 config, make sure that all of the
OpenStack modules handle the inbound auth config in the same way.
The one outlier is keystone wrt auth_url.
The provisioning module knows more about how nova deals with IP
addresses now. Ensure that the inventory module is similarly as smart
by separating out the logic into the openstack/module_utils.
Taking a page out of the ec2 config, make sure that all of the
OpenStack modules handle the inbound auth config in the same way.
The one outlier is keystone wrt auth_url.