- Move the core ros files from PREFIX/ros to PREFIX/ros/ros, this is
necessary to be able to upgrade add-on packages (like ros_tutorials) in
place due to the way rosmake searches for packages.
- Update ros/pkg-descr and ros_tutorials to reflect this
- Partially fix build with Clang (ros does not link yet)
- Makefile cleanups for devel/ros
- Bump PORTREVISIONs