Fixes jashkenas#2152 -- support PATCH in IE <= 8

backbone.js

@@ -1445,6 +1445,15 @@
       params.processData = false;
     }
 
+    // If we're sending a `PATCH` request, and we're in an old Internet Explorer
+    // that still has ActiveX enabled by default, override jQuery to use that
+    // for XHR instead. Remove this line when jQuery supports `PATCH` on IE8.
+    if (params.type === 'PATCH' && window.ActiveXObject) {
+      params.xhr = function() {
+        return new ActiveXObject("Microsoft.XMLHTTP");
+      };
+    }
+
     // Make the request, allowing the user to override any Ajax options.
     var xhr = options.xhr = Backbone.ajax(_.extend(params, options));
     model.trigger('request', model, xhr, options);