Clean up CSS

- Add vim folds to make organized sections
- Rename a lot of classes from post- to page-
- Generalize series CSS classes better
- Clean up navbar div structure
- Remove langpicker and most of multilingual support
- many other minor tweaks

layouts/authors/list.html

@@ -11,7 +11,7 @@
     <div class="page-list">
         {{ with .Paginator.Pages }}
             {{ range . }}
-                <article class="post">
+                <article class="page">
                     {{ .Render "summary" }}
                 </article>
             {{ end }}