Improve no-auth path

The commands that do not require authentication sometimes still need
to call ClientManager.is_network_endpoint_enabled() to see if Neutron
is available.  Optimize the paths a bit to skip auth when it is not
necessary; the upshot is Neutron will be assumed in these cases now.

This gets a LOT cleaner when it appears is a future osc-lib.

Change-Id: Ifaddc57dfa192bde04d0482e2cdcce111313a22a

openstackclient/shell.py

@@ -182,6 +182,12 @@ class OpenStackShell(shell.OpenStackShell):
         #                get_one_Cloud()'s validation to avoid loading plugins
         validate = cmd.auth_required
 
+        # Force skipping auth for commands that do not need it
+        # NOTE(dtroyer): This is here because ClientManager does not have
+        #                visibility into the Command object to get
+        #                auth_required. It needs to move into osc-lib
+        self.client_manager._auth_required = cmd.auth_required
+
         # Validate auth options
         self.cloud = self.cloud_config.get_one_cloud(
             cloud=self.options.cloud,