Updated chromedriver download methodology.

* Utilize S3 bucket XML instead of parsing HTML
* Encapsulate download URL logic in GoogleCodeParser
* Always re-fetch zip archive, because filenames all look the same
* Updated specs.
Plain HTTP for spec URLs
fix downloads on windows

fix windows file path problems
fix spacings
Merge pull request #1 from elementc/download-via-bucket-xml

pull in mars' and my changes.