preserve backward-compatible $([IPython.events])

IPython/html/static/base/js/events.js

@@ -13,7 +13,7 b" define(['base/js/namespace', 'jquery'], function(IPython, $) {"
 
     var Events = function () {};
     
-    var events = $([new Events()]);
+    var events = new Events();
     
     // Backwards compatability.
     IPython.Events = Events;

IPython/html/static/notebook/js/main.js

@@ -125,7 +125,6 b' require(['
     IPython.menubar = menubar;
     IPython.toolbar = toolbar;
     IPython.notification_area = notification_area;
-    IPython.events = events;
     IPython.keyboard_manager = keyboard_manager;
     IPython.save_widget = save_widget;
     IPython.config = user_config;

IPython/html/static/tree/js/main.js

@@ -99,7 +99,6 b' require(['
     IPython.session_list = session_list;
     IPython.kernel_list = kernel_list;
     IPython.login_widget = login_widget;
-    IPython.events = events;
 
     events.trigger('app_initialized.DashboardApp');