Updated codemirror to v4.12.

Did a lot of cleanup to limit the size of the plugin.
I kept the emmet plugin.

applications/admin/static/codemirror/mode/r/index.html

@@ -15,12 +15,12 @@
       .cm-s-default span.cm-arg-is { color: brown; }
     </style>
 <div id=nav>
-  <a href="http://codemirror.net"><img id=logo src="../../doc/logo.png"></a>
+  <a href="http://codemirror.net"><h1>CodeMirror</h1><img id=logo src="../../doc/logo.png"></a>
 
   <ul>
     <li><a href="../../index.html">Home</a>
     <li><a href="../../doc/manual.html">Manual</a>
-    <li><a href="https://github.com/marijnh/codemirror">Code</a>
+    <li><a href="https://github.com/codemirror/codemirror">Code</a>
   </ul>
   <ul>
     <li><a href="../index.html">Language modes</a>
@@ -80,7 +80,6 @@ powerful <- function(x) {list(x2=x*x, x3=x*x*x, x4=x*x*x*x)}
     <p><strong>MIME types defined:</strong> <code>text/x-rsrc</code>.</p>
 
     <p>Development of the CodeMirror R mode was kindly sponsored
-    by <a href="http://ubalo.com/">Ubalo</a>, who hold
-    the <a href="LICENSE">license</a>.</p>
+    by <a href="https://twitter.com/ubalo">Ubalo</a>.</p>
 
   </article>