support h1-h6, fixes #516

source/Ox.UI/css/Ox.UI.css

@@ -33,11 +33,14 @@ div, input, textarea {
     font-family: Lucida Grande, Segoe UI, DejaVu Sans, Arial;
     font-size: 11px;
 }
-h1 {
+h1,h2,h3,h4,h5,h6 {
     margin: 0;
     font-size: 16px;
     font-weight: normal;
 }
+h2,h3,h4,h5,h6 {
+    font-size: 14px;
+}
 img {
     -moz-user-drag: none;
     -o-user-drag: none;

source/Ox/js/HTML.js

@@ -46,7 +46,7 @@ Ox.parseHTML = (function() {
             // inline formatting
             'b', 'code', 'i', 's', 'sub', 'sup', 'u',
             // block formatting
-            'blockquote', 'h1', 'p', 'pre',
+            'blockquote', 'h1', 'h2', 'h3', 'p', 'pre',
             // lists
             'li', 'ol', 'ul',
             // tables