Fixes #2610 (attempt 2).

Works-around the IE 9 login problem without modifying vendor/backbone.js.

Tested with IE 9.0.4.

public/javascripts/ie.js

 document.createElement('header');
-document.createElement('footer');
\ No newline at end of file
+document.createElement('footer');
+
+// IE 9 work-around for vendor/backbone.js
+if ((window.history) && (document.documentMode == 9)) {
+	window.history.pushState = function() { };
+}