Node 0.10.0 and Linux support

I've added conditions to use different libraries depending on the OS in binding.gyp.

Up to you to accept change for node 0.10.0/

I also changed the README as multi user does work (well it did when I tried out the skeleton example in node-openni-browser).

Also removed unnecessary whitespace on the files I edited (although that was vim not me).

Anyway, fun project!