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

* remotes/upstream/master:
  turn registration code into a standalone function for re-use
  query using both `id` and `parent`
  prevent email from leaking in feeds
  y didn't i think of this b4?
  some zero theming on settings page
  missing delimiter
  transition to beta for private forums
  rev update
  Friendicaland - you can't 'live' on a demo server.
  Create a "potential default group" called "Friends" on registration.
  fix private photos that also have a size specification
  private group tests, cont.
  hide private group if desired
  prvgroup should see intros
  private group fix
  possible sql injection in search
  bugfixes: private photo embeds and search for strings with %

* master: