Eclipse project files

Pull request adds various Eclipse settings files, making it easy to set up Drake as an Eclipse project. I also created a guide that explains how to set it all up:
https://github.com/tkoolen/drake/wiki/Eclipse-setup-(experimental)

I set it up from scratch several times today and polished the setup procedure. I'm fairly confident that it should work on somebody else's Mac. Not too sure about Linux yet. If you find the time to try out the guide, please let me know if everything works and is clear enough.