Add support for argparse Namespace objects
Add support for argparse Namespace objects

The Namespace objects returned by argparse contain all defined options
even if they are unspecified and default to None or ''.  Also it
is not iterable.  Change all that to add only the options presented
to argparse to the cloud_config.

Change-Id: Ia22fad60c81ab0b2878b404c0c8608d903ca964b

redhat-openstack/os-client-config,openstack/os-client-config,dtroyer/python-openstacksdk,stackforge/python-openstacksdk,stackforge/python-openstacksdk,dtroyer/os-client-config,switch-ch/os-client-config,openstack/python-openstacksdk,openstack/python-openstacksdk,dtroyer/python-openstacksdk