Move binding to IPython global one level up the stack

notebook/static/tree/js/main.js

@@ -39,6 +39,8 @@ require([
     loginwidget){
     "use strict";
 
+    IPython.NotebookList = notebooklist.NotebookList;
+
     page = new page.Page();
     
     var common_options = {

notebook/static/tree/js/notebooklist.js

@@ -874,9 +874,5 @@ define([
             .append(cancel_button);
     };
 
-
-    // Backwards compatability.
-    IPython.NotebookList = NotebookList;
-
     return {'NotebookList': NotebookList};
 });