add timestamp to title for published and scheduled pages on page index

app/views/admin/pages/_node.html.haml

@@ -12,7 +12,7 @@
             = spinner
     - node.status_column do
       - unless simple
-        %td.status{:class => "#{page.status.name.downcase}_status"}= page.status.name
+        %td.status{:class => "#{page.status.name.downcase}_status", :title => "#{timestamp(page.published_at) if page.published_at}"}= page.status.name
     - node.add_child_column do
       - unless simple
         %td.add_child= link_to image('add_child', :alt => 'add child'), new_admin_page_child_url(page)