Improve the context of error messages
Improve the context of error messages

- don't print more than we need to (it's easier to read less info)
- add an error when the user provides a wrong action

Change-Id: I8f477353849981446ba101f8097fe95b49c587d9

ed-/python-solumclient,ed-/python-solumclient,stackforge/python-solumclient,openstack/python-solumclient,rackerlabs/arborlabs_client,stackforge/python-solumclient,rackerlabs/arborlabs_client