Remove use of $.browser (removed in jQuery 1.9) and use regex

Fixes cowboy#42

Ideally we'd improve the feature test to not need this but looks
like we still need it for IE6/7 which pass the feature test but
do need this override in order to work properly.

jquery.ba-hashchange.js

@@ -297,7 +297,7 @@
     // vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
     // vvvvvvvvvvvvvvvvvvv REMOVE IF NOT SUPPORTING IE6/7/8 vvvvvvvvvvvvvvvvvvv
     // vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
-    $.browser.msie && !supports_onhashchange && (function(){
+    /MSIE/.test(navigator.userAgent) && !supports_onhashchange && (function(){
       // Not only do IE6/7 need the "magical" Iframe treatment, but so does IE8
       // when running in "IE7 compatibility" mode.