Toggle line numbers in menu

use 'Toggle' text, instead of switching between Show/Hide

IPython/html/static/edit/js/menubar.js

@@ -115,10 +115,6 @@ define([
         });
         
         this.events.on("config_changed.Editor", function () {
-            var lineNumbers = editor.codemirror.getOption('lineNumbers');
-            var text = lineNumbers ? "Hide" : "Show";
-            text = text + " Line Numbers";
-            that.element.find('#menu-line-numbers').find("a").text(text);
             var keyMap = editor.codemirror.getOption('keyMap') || "default";
             that.element.find(".selected-keymap").removeClass("selected-keymap");
             that.element.find("#menu-keymap-" + keyMap).addClass("selected-keymap");

IPython/html/templates/edit.html

@@ -60,7 +60,7 @@ data-file-path="{{file_path}}"
             </li>
             <li class="dropdown"><a href="#" class="dropdown-toggle" data-toggle="dropdown">View</a>
               <ul id="view-menu" class="dropdown-menu">
-                <li id="menu-line-numbers"><a href="#">Hide Line Numbers</a></li>
+                <li id="menu-line-numbers"><a href="#">Toggle Line Numbers</a></li>
               </ul>
             </li>
             <li class="dropdown"><a href="#" class="dropdown-toggle" data-toggle="dropdown">Mode</a>