service catalog parsing should be delegated to keystoneclient

[Lin Hua Cheng]

Horizon or django_openstack_auth should not be manually parsing the service catalog and determining the logic for v2/v3 catalog.

Ideally, keystoneclient should be leverage for endpoint looking in the service catalog.

Preferably using the auth_plugin to perform the endpoint lookup, if not available another thing to look at is the ServiceCatalog object.

[Matthias Runge (mrunge)]

I think this should be generalized in django-openstack-auth (or plugin there)