Fix issues related to System.resolve and System.normalize on Node

1. The module loader was setting the referrer even for `type == 'module'`. The code gen for module is surrounded by registerModule which now resolves the `System.set`, causing us to do a double resolve. This works fine in a browser because we have an absolute URL but in Node.js it is relative paths.

2. The test used window.location.href or __filename. The file name path is not working well. I change the test to not depend on the environment.

Fixes #396

Review URL: https://github.com/google/traceur-compiler/pull/400

Closes #400, closes #396.