cmake: remove ROS specific build instructions and educate the user.

Signed-off-by: Peter Soetens <peter@thesourceworks.com>
catkin: provide catkin compatible package.xml file

Signed-off-by: Ruben Smits <ruben.smits@intermodalics.eu>
cmake: add NO_ROS_PACKAGE statement since UseOrocos.cmake gets confused in a plain cmake catkin build

Signed-off-by: Ruben Smits <ruben@intermodalics.eu>
Merge remote-tracking branch 'orocos/master'