Added markdown parsing for comments so links in comments now appear properly.

Also rewrote part of the HTML rewriting code so it doesn't introduce an additional wrapping element in the output which was added due to a html5lib requirements on input.

python/media/css/main.css

@@ -278,6 +278,12 @@ li .post-comment-text {
     margin-bottom: 0;
 }
 
+/* this rule is needed as comments are wrapped in <p>...</p> but we want the
+ * user name afterwards to appear on the same line. */
+li .post-comment-text > p {
+    display: inline;
+}
+
 li .post-comment-metadata {
     color: #999999;
 }