Folded in remote file upload functionality for NodeJS from sergeyksv

 https://github.com/sergeyksv/selenium-webdriver-gh/commit/8133faf3494c7c7c36f238bbcaf63fea07e0ad25.

This is similar to the remote file upload functionality in Java and Ruby and is needed for use with a service like Sauce Labs. To activate, something akin to the following line is used:
```
driver.setFileDetector(webdriver.FileDetector.LocalFileDetector);
```
Actually Selenium's `uploadFile` command require a full zip archive containing a single file : 
https://github.com/SeleniumHQ/selenium/blob/master/java/server/src/org/openqa/selenium/remote/server/handler/UploadFile.java#L39-L50

Such a file can't be produced using zlib only without re-implementing the full zip spec.