Force sockjs 0.3.7 - problematic frames
Not-found safety; remove bodyParser; group tests

 - Add safety checks throughout to prevent utils.can_edit from throwing
   errors for undefined documents, which are a source of occasional
   crashes right now.
 - replace express.bodyParser with express.json and express.urlencoded.
   For the one function that uses multipart files (group logo uploads),
   add ``multiparty``, and invoke it directly in that route rather than
   as global middleware.
 - Improve tests for group logos and group membership editing.  Fix
   tests so they work with latest installed versions of email libraries
   (which introduced some asynchronous lag).
Merge branch 'master' of ella.intertwinkles.org:/var/intertwinkles