Add IE9 on Windows 7 status.

Browser-support.md

@@ -90,6 +90,20 @@ This list show results of testing noVNC on various browser and OS combinations.
 </table>
 
 
+### Windows 7
+
+<table>
+    <tr>
+        <th>Browser</th>
+        <th>Status</th>
+        <th>Performance/Notes</th>
+    </tr> <tr>
+        <td>IE 9</td>
+        <td>Good</td>
+        <td>Slow. Similar to Firefox 3.6 (but 2X slower for tightPNG)</td>
+    </tr>
+</table>
+
 ### Windows XP
 
 <table>