fg21sim: v0.3.0

* Major change to the Web UI.
  + The WebSocket is only used to push configurations and logging
    messages to the client;
  + The configuration manipulations and console operations are
    implemented using the AJAX techniques;
  + Modal box is used to notify the AJAX request results,
    therefore much better user experience.

* Several bug fixes to the Web UI.

* Minor improvements to the simulation parts.

* TODO/problems:
  + The console task currently still blocks the Tornado IO loop!
  + The Web UI "results" section is not implemented yet.
  + The "extragalactic/pointsources" component is not added to
    Web UI configurations yet.