Check for classList support on SVG element

IE supports classList but not on SVG elems so favouriting nodes fails halfway through if we only check for classList on generic elems.

public/assets/enhancements.js

@@ -55,7 +55,11 @@
       ) == 'http://www.w3.org/2000/svg';
     })(),
     querySelector: typeof doc.querySelector === 'function',
-    classList: 'classList' in create('div')
+    classList: (function() {
+      var div = create('div');
+      div.innerHTML = '<svg/>';
+      return 'classList' in div.firstChild;
+    })(),
   });
 
   // Favourite nodes