OOP like modifications.

geometry/Arc.cpp

geometry/Arc.h

geometry/Path.cpp

geometry/Path.h

geometry/Segment.cpp

geometry/Segment.h

geometry/Shape.cpp

geometry/Shape.h

planner/AlternativePlanner.cpp

planner/AlternativePlanner.h

planner/CCS.cpp

planner/CCS.h

planner/Environment.cpp

planner/Environment.h

planner/LocalPlanner.cpp

planner/LocalPlanner.h

planner/Scene.cpp

planner/Scene.h