support html representations in the notebook frontend

html gets highest priority, because it is the native language
of the frontend.

IPython/frontend/html/notebook/static/css/notebook.css

@@ -285,6 +285,9 @@ div.output_latex {
     font-size: 116%;
 }
 
+div.output_html {
+}
+
 div.output_png {
 }
 

IPython/frontend/html/notebook/static/js/codecell.js

@@ -175,7 +175,9 @@ var IPython = (function (IPython) {
 
 
     CodeCell.prototype.append_display_data = function (data, element) {
-        if (data["text/latex"] !== undefined) {
+        if (data["text/html"] !== undefined) {
+            this.append_html(data["text/html"], element);
+        } else if (data["text/latex"] !== undefined) {
             this.append_latex(data["text/latex"], element);
             // If it is undefined, then we just appended to div.output, which
             // makes the latex visible and we can typeset it. The typesetting
@@ -194,6 +196,15 @@ var IPython = (function (IPython) {
     };
 
 
+    CodeCell.prototype.append_html = function (html, element) {
+        element = element || this.element.find("div.output");
+        var toinsert = $("<div/>").addClass("output_area output_html");
+        toinsert.append(html);
+        element.append(toinsert);
+        return element;
+    }
+
+
     CodeCell.prototype.append_stream = function (data, element) {
         element = element || this.element.find("div.output");
         var toinsert = $("<div/>").addClass("output_area output_stream");