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/jinja2/index.html

@@ -9,12 +9,12 @@
 <script src="jinja2.js"></script>
 <style type="text/css">.CodeMirror {border-top: 1px solid black; border-bottom: 1px solid black;}</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>
@@ -25,22 +25,26 @@
 <article>
 <h2>Jinja2 mode</h2>
 <form><textarea id="code" name="code">
-&lt;html style="color: green"&gt;
-  &lt;!-- this is a comment --&gt;
-  &lt;head&gt;
-    &lt;title&gt;Jinja2 Example&lt;/title&gt;
-  &lt;/head&gt;
-  &lt;body&gt;
-    &lt;ul&gt;
-    {# this is a comment #}
-    {%- for item in li -%}
-      &lt;li&gt;
-        {{ item.label }}
-      &lt;/li&gt;
-    {% endfor -%}
-    &lt;/ul&gt;
-  &lt;/body&gt;
-&lt;/html&gt;
+{# this is a comment #}
+{%- for item in li -%}
+  &lt;li&gt;{{ item.label }}&lt;/li&gt;
+{% endfor -%}
+{{ item.sand == true and item.keyword == false ? 1 : 0 }}
+{{ app.get(55, 1.2, true) }}
+{% if app.get(&#39;_route&#39;) == (&#39;_home&#39;) %}home{% endif %}
+{% if app.session.flashbag.has(&#39;message&#39;) %}
+  {% for message in app.session.flashbag.get(&#39;message&#39;) %}
+    {{ message.content }}
+  {% endfor %}
+{% endif %}
+{{ path(&#39;_home&#39;, {&#39;section&#39;: app.request.get(&#39;section&#39;)}) }}
+{{ path(&#39;_home&#39;, {
+    &#39;section&#39;: app.request.get(&#39;section&#39;),
+    &#39;boolean&#39;: true,
+    &#39;number&#39;: 55.33
+  })
+}}
+{% include (&#39;test.incl.html.twig&#39;) %}
 </textarea></form>
     <script>
       var editor =