Adds the Scheduled Images extension.

Includes the Scheduled Images extension extension.
Changed the test_scheduled_images.py
Working unit test test_show_server

in file nova/tests/api/openstack/compute/contrib/test_scheduled_images.py
Cleaned up more tests in test_scheduled_images.py
all unit tests passing except restricted by project
extension unit tests passing
Cleaned up pip errors and Comments
Changed ext to use Tenant name istead of ID
_create_image_schedule includes server_id