Add more goodies

Client side:
- Parameterize asset location and API tokens via Jade config in settings.json;
- Add meta keywords and remove special chars (integrated from gh-pages);
- Add loading progress indicator;
- Add option to cleanup local storage;
- Add option to input partial URLs (no 'http://');
- Add alternative parsing API method.

Server side:
  - Parameterize token in the server app.yaml settings;
  - Allow CORS from anywhere (guarded by token);
  - Fix server encoding exception.