Reset file upload form after an upload.

IPython/html/static/tree/js/notebooklist.js

@@ -92,6 +92,11 @@ var IPython = (function (IPython) {
                 });
             }
         }
+        // Replace the file input form wth a clone of itself. This is required to
+        // reset the form. Otherwise, if you upload a file, delete it and try to 
+        // upload it again, the changed event won't fire.
+        var form = $('input.fileinput');
+        form.replaceWith(form.clone(true));
         return false;
     };