Correct capitalization in menu.

IPython/html/templates/notebook.html

@@ -111,7 +111,7 b' data-notebook-path="{{notebook_path}}"'
                         <li class="divider"></li>
                         <li id="kill_and_exit"
                             title="Shutdown this notebook's kernel, and close this window">
-                            <a href="#" >Close and halt</a></li>
+                            <a href="#" >Close and Halt</a></li>
                     </ul>
                 </li>
                 <li class="dropdown"><a href="#" class="dropdown-toggle" data-toggle="dropdown">Edit</a>