Merge remote-tracking branch 'remotes/upstream/master'

* remotes/upstream/master:
  service class restrict the email connector
  stray s
  typos
  add event titles to discovered birthday events
  change required doco
  change event behaviour so that title is required but description is not
  event summary/title
  propagate remote deletes
  remove possibly unnecessary checks for likes or comments created by Diaspora users
  store signature info for remote users too
  was passing the wrong arguments to the signature storage function
  add some debug logging
  revert extra Diaspora disabling changes to try to eliminate Mustard double-posting
  Clean up the Diaspora connectivity:
  improve remote delete forwarding
  typos in bbcode, add service class restrictions to jot uploads
  rev update