anchor.diff:    + per_page (optional, integer) ... number of items to include on a page default is 20
     + subject_id (optional, integer) ... id of subject to see set_member_subjects for
     + subject_set_id (optional, integer) ... id of subject_set to see set_member_subjects for
  -  + language (optional, string) ... language code to search for
     + include (optional, string) ... comma seperated list of linked resources to load
     
   + Response 200
   
       [SetMemberSubject Collection][]
   
  -### Create a SetMemberSubject
  +### Create a SetMemberSubject [POST]
   A SetMemberSubject may be created by a user that can see the Subject
   they wish to link to and can edit the project the SubjectSet belongs
   to.
  
positive.code: 
  + Response 204
  
  ## Subject Version [/workflow_contents/{workflow_contents_id}/versions/{id}]
  A Subject Version resource represents a set of changes made to
  a Subject resource.
  
  
negative.code: 
  + Response 204
  
  ## Classification Collection [/classifications{?page,per_page,sort,project_id,group_id,include}]
  A representation of all the Classifications in a collection
  
  All collections add a *meta* attribute hash containing
  