Notification + tooltip demo

Use notification to quicky remind use of the tooltip

Use javascript in notebook to make a live demo in
01_notebook_introduction

tooltip docstring is remplaceid for the first use by a live tutorial

IPython/frontend/html/notebook/static/js/tooltip.js

@@ -123,9 +123,18 @@ var IPython = (function (IPython) {
         this.tooltip.append(this.text);
 
         // function that will be called if you press tab 1, 2, 3... times in a row
-        this.tabs_functions = [  function(cell,text){that._request_tooltip(cell,text)},
-                                 function(){that.expand()},
-                                 function(){that.stick()},
+        this.tabs_functions = [  function(cell,text){
+                                    that._request_tooltip(cell,text);
+                                    IPython.notification_widget.set_message('tab again to expand pager',2500);
+                                    },
+                                 function(){
+                                    that.expand();
+                                    IPython.notification_widget.set_message('tab again to make pager sticky for 10s',2500);
+                                 },
+                                 function(){
+                                     that.stick();
+                                     IPython.notification_widget.set_message('tab again to open help in pager',2500);
+                                 },
                                  function(cell){
                                     that.cancel_stick();
                                     that.showInPager(cell);