Skip language tests on broken browsers

The hacks needed to run these tests require proper handling of
properties. Unfortunately IE and old versions of Chrome mess up,
so just skip the tests there.

tests/test.util.js

@@ -63,7 +63,19 @@ describe('Utils', function() {
             // environments, so we need to redefine it whilst running these
             // tests.
             origNavigator = Object.getOwnPropertyDescriptor(window, "navigator");
+            if (origNavigator === undefined) {
+                // Object.getOwnPropertyDescriptor() doesn't work
+                // properly in any version of IE
+                this.skip();
+            }
+
             Object.defineProperty(window, "navigator", {value: {}});
+            if (window.navigator.languages !== undefined) {
+                // Object.defineProperty() doesn't work properly in old
+                // versions of Chrome
+                this.skip();
+            }
+
             window.navigator.languages = [];
         });
         afterEach(function () {