Write restful service to find all orphans
To help fix recent bugs re orphaned discussions and
to prototype a more restful json oriented api.
Add delete if staff member
Limit read access to people with write access.

Add unit tests for auth
Separate doc_store_config
Use new restful pattern instead
Merge pull request #1191 from edx/dhm/orphan_finder

Write restful service to find all orphans