Allow for existence of query-string parameters in URL

The current `UrlResolver.js` does not account for dependency URLs that contain a querystring.

I am currently working on a project that has some dependencies that require a `?raw` querystring at the end of the URL.

On Unix systems this results in a file being saved as `somefile.js?raw` (no extension), and on Windows the process blows up as NTFS doesn't allow for filenames that contain a `?`.

By passing the filename through `url.parse`, and extracting the `pathname` from the result, this issue can be resolved.