OR-833 External file for Tuple schema
OR-833 User Notification model uses the shared Tuple schema
OR-833 Base collaboration schema builder

This method takes a mongoose JSON schema definition, it adds:
- the creator property (userid)
- the domain_ids array (array of domain ids)
- the timestamps object
- the members array (taking the hypothesis that a collaboration always involves
  a bunch of resources that collaborates together)
- the activity_stream property
- the injections property

It returns a Mongoose schema, that can be augmented (constants, middlewares...)
OR-833 community mongoose schema uses the collaboration schema builder
Merge pull request #599 in OR/rse from ~MBAILLY/rse:OR-833-create-a-base-collaboration-model to master

* commit '239b7200ae9b3eab1bdc32488ec3dcd70ffa833b':
  OR-833 community mongoose schema uses the collaboration schema builder
  OR-833 Base collaboration schema builder
  OR-833 User Notification model uses the shared Tuple schema
  OR-833 External file for Tuple schema