Merge pull request #1624 from velesin/qunit_fixture_helpers

adds QUnit test helper simplifying usage of #qunit-fixture

test/javascripts/helpers/qunit_helpers.js

@@ -39,4 +39,11 @@ function asyncTestDiscourse(text, func) {
       func.call(self);
     });
   });
-}
+}
+
+function fixture(selector) {
+  if (selector) {
+    return $("#qunit-fixture").find(selector);
+  }
+  return $("#qunit-fixture");
+}