Windows support (in particular for the path lib)

Basically, my issue is this: https://github.com/substack/path-browserify/issues/1

Summary: Easily fixed in path-browserify, but it depends on process.platform being available, which it cannot be as it is done right now since the process lib is only defining an object. I.e. in order for process.platform to be properly set there needs to be some kind of preprocessing server-side of the process script so that we can get the server's process values.

Any clues? This would probably fit best in some kind of option but right now it doesn't seem easily doable?