moved vendor js files to common

lms/static/coffee/src/customwmd.coffee

 $ ->
   converter = Markdown.getSanitizingConverter()
   editor = new Markdown.Editor(converter)
-  converter.hooks.chain "preConversion", removeMath
+  #converter.hooks.chain "preConversion", removeMath
   editor.run()

lms/templates/discussion/index.html

@@ -8,6 +8,9 @@
 </%block>
 
 <%block name="js_extra">
+  <script type="text/javascript" src="${static.url('js/vendor/Markdown.Converter.js')}"></script>
+  <script type="text/javascript" src="${static.url('js/vendor/Markdown.Sanitizer.js')}"></script>
+  <script type="text/javascript" src="${static.url('js/vendor/Markdown.Editor.js')}"></script>
 </%block>
 
 <%include file="../course_navigation.html" args="active_page='discussion'" />