Add :publicly_available to Templates

Now Templates can be public or non-public.  This exposes the public flag on
images from cloud providers.

For Openstack, this information is available on the detailed image information
retrieved from the Openstack Glance API.

For Amazon, to avoid making an additional EC2 API call per image, the
:publicly_available information is derived from how the images are gathered by
the EC2 Parser.  For instance, get_private_images sets :publicly_available =
false, and get_public_images sets :publicly_available = true.
Merge pull request #651 from blomquisg/publicly-available-images

Add :publicly_available to Templates
Modify ManageIQ/Infrastructure/vm/retirement statemachine and method
classes for combining delete and unregister provider.

Class - remove unregisterfromprovider state.
Remove instance display names.
Rename delete_from_provider_check method to check_delete_from_provider
Modified delete_from_provider method to have option for delete and
unregister, added unregister code, and changed method criteria to
check for vm archived or orphaned instead of host.nil.
Modified Default instance to reflect provider changes.

https://bugzilla.redhat.com/show_bug.cgi?id=1074532