Uncaught ReferenceError: CodeMirror is not defined

You're loading the clike module before CodeMirror itself.

Change the order in your HTML head from this:

<script type="text/javascript" src="../CodeMirror-2.33/mode/clike/clike.js"></script>
<script type="text/javascript" src="../CodeMirror-2.33/lib/codemirror.js"></script>
<script type="text/javascript" src="../CodeMirror-2.33/mode/javascript/javascript.js"></script>

To this:

<script type="text/javascript" src="../CodeMirror-2.33/lib/codemirror.js"></script>
<script type="text/javascript" src="../CodeMirror-2.33/mode/clike/clike.js"></script>
<script type="text/javascript" src="../CodeMirror-2.33/mode/javascript/javascript.js"></script>