(robot-compile-setup.sh) Use fixed folder name for model file, download latest NXO zipball

just a commnet, it is ok, but someday you will have trouble on someone will push broken model to hydro-devel and you did not notice about that. so fixing version is always safer, specially for the robot you that located on different site and different admin (which you did not maintain everyday).

please remember this comment if you have trouble.