C++14 is default in clang/gcc anyway and latest log4cxx requires C++17.
Qt on Ubuntu 18.04 sets C++11. Hence we use MoveIt's cmake macro to ensure C++14 at least.
Implement visualization as red-green arrow
* overload makeArrow to allow creation with points
* create new function for visualization
* if no plan is found, construct arrow from green cylinder and red arrow
* adjust arrow construction for backward propagators