Options for javascript execution

Sometimes while writing tests it might be useful to enable javascript execution in jsdom, especially for libraries that deal with DOM events (like a small script loader for browsers, like in my case). So I added two more options to nodeunit-b, in order to allow script processing and/or external resource fetching:

    processScripts: true|false           //Defaults to false
    fetchExternalResources: true|false   //Defaults to false

While writing the tests for these two new options, I noticed that the tests failed on Windows (because of different path separator), so I fixed the tests using `path.normalize()` (I couldn't figure out a better solution). Now the rests run fine on both Windows and Linux (I tried Windows 8 and Ubuntu 13.04).

Thank you in advance for your consideration!