Add tooltips to the notebook via 'title' attr.

All buttons, show/hide clickable areas, etc. should have some tooltip describing
what they do.  There are jQuery plugins for enhanced tooltips, but this gets
the lightest version working.

closes #436

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

@@ -26,6 +26,7 @@ var IPython = (function (IPython) {
     Pager.prototype.style = function () {
         this.pager_splitter_element.addClass('border-box-sizing ui-widget ui-state-default');
         this.pager_element.addClass('border-box-sizing ui-widget');
+        this.pager_splitter_element.attr('title', 'Click to Show/Hide pager area');
     };
 
 

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

@@ -22,6 +22,7 @@ var IPython = (function (IPython) {
 
     QuickHelp.prototype.style = function () {
         this.element.find('button#quick_help').button();
+        this.element.find('button#quick_help').attr('title', "Show/Hide the keyboard shortcuts for the IPython Notebook");
     };
 
     QuickHelp.prototype.bind_events = function () {

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

@@ -29,6 +29,7 @@ var IPython = (function (IPython) {
         this.element.find('input#notebook_name').addClass('ui-widget ui-widget-content');
         this.element.find('input#notebook_name').attr('tabindex','1');
         this.element.find('button#save_notebook').button();
+        this.element.find('button#save_notebook').attr('title', 'Save the Notebook');
         var left_panel_width = $('div#left_panel').outerWidth();
         var left_panel_splitter_width = $('div#left_panel_splitter').outerWidth();
         $('span#save_widget').css({marginLeft:left_panel_width+left_panel_splitter_width});

IPython/frontend/html/notebook/templates/notebook.html

@@ -169,7 +169,7 @@
                     <span id="autoindent_span">
                         <input type="checkbox" id="autoindent" checked="true"></input>
                     </span>
-                    <span class="checkbox_label">Autoindent:</span>
+                    <span class="checkbox_label" id="autoindent_label">Autoindent:</span>
                 </div>
             </div>
         </div>
@@ -188,7 +188,7 @@
                     <span id="kernel_persist">
                         <input type="checkbox" id="kill_kernel"></input>
                     </span>
-                    <span class="checkbox_label">Kill kernel upon exit:</span>
+                    <span class="checkbox_label" id="kill_kernel_label">Kill kernel upon exit:</span>
                 </div>
             </div>
         </div>