Merge remote-tracking branch 'origin/master' into stack-annotation

* origin/master:
  Properly fix Facebook group fetching
  Added pyzmq as the dependency
  Adding documentation on how to build submodules
  Fix proper error reporting
  fixed run_websocket way of running websocket app
  Improved build instructions for fresh clone of repository
Better stack interpolation, and correcting errors
Merge branch 'master' of github.com:SlideAtlas/SlideAtlas-Server into stack-annotation
Merge branch 'stack-annotation'

* stack-annotation:
  Better stack interpolation, and correcting errors