clean: add an additional check before removing directories outside of the workspace root (keep people from accidentally blowing away their system prefix)
clean: add an additional check before removing directories outside of the workspace root (keep people from accidentally blowing away their system prefix)

scpeters/catkin_tools,rhaschke/catkin_tools,scpeters/catkin_tools,catkin/catkin_tools,scpeters/catkin_tools,rhaschke/catkin_tools,catkin/catkin_tools,catkin/catkin_tools,rhaschke/catkin_tools,catkin/catkin_tools,scpeters/catkin_tools