Multi-facetted fix for issue #23
 - Reset the permission scope used when setting the owner permission in the CRUD view,
   because it's meaningless (and wrong) to have a scoped owner permission
 - Only consider scoped perms if their target is a content type (because otherwise
   things have gone wrong.)
 - Check the calculated perms are output correctly by the ACL manager.
 - Add another ACL test to check for correct scoped permission setting.
 - Add a check to ensure no owner permissions have been granted with a scope.