Templated catalog does not handle multi-regions properly

The current implementation of the keystone templated catalog does not group endpoints properly when there are multiple regions available.

This is an working example when using the sql backend and the openstack catalog list command.

| nova | compute | RegionTwo
| | | admin: http://10.0.3.15:8774/v2.1
| | | RegionOne
| | | admin: http://10.0.2.15:8774/v2.1

This is the same example using the templated backend and the openstack catalog list command.

| nova | compute | RegionTwo
| | | admin: http://10.0.3.15:8774/v2.1
| nova | compute | RegionOne
| | | admin: http://10.0.2.15:8774/v2.1

This causes issues in services that expects each service_type to include the endpoint for all regions.

This is because the code in for example Horizon is initially only looking for the service_type, which will return the first one, in this case is RegionTwo. If Horizon was requesting RegionOne, this would fail, as the list of endpoints would only contain RegionTwo.

As a work-around for Horizon a change like this is required
http://paste.openstack.org/show/614967/

 -def get_service_from_catalog(catalog, service_type):
 +def get_service_from_catalog(catalog, service_type, region):
      if catalog:
          for service in catalog:
              if 'type' not in service:
                  continue
              if service['type'] == service_type:
 - return service
 + for endpoint in service['endpoints']:
 + if endpoint['region'] == region:
 + return service
      return None