Initial cut at saving/retrieving the main browser layout.

Still needs some work to:

- Minimise AJAX calls by writing multiple settings at once.
- Move the settings storage/retrieval JS code into a global file
- Avoid using synchronous AJAX calls in the main thread

web/pgadmin/templates/base.html

@@ -41,6 +41,7 @@
         <script src="{{ url_for('static', filename='js/vendor/alertifyjs/alertify.min.js') }}"></script>
         <script src="{{ url_for('static', filename='js/vendor/jquery-ui/jquery-ui.min.js') }}"></script>
         <script src="{{ url_for('static', filename='js/vendor/jquery-layout/jquery.layout.min.js') }}"></script>
+        <script src="{{ url_for('static', filename='js/vendor/jquery-layout/plugins/jquery.layout.state.js') }}"></script>
         <script src="{{ url_for('static', filename='js/main.js') }}"></script>
         
         <script>