Merge branch 'virtualCouplingObject' into 'master'

...CollisionDetection/imstkUnidirectionalPlaneToSphereCD.cpp

Base/Collision/CollisionHandling/imstkCollisionHandling.cpp

Base/Collision/CollisionHandling/imstkCollisionHandling.h

Base/Collision/CollisionHandling/imstkVirtualCouplingCH.cpp

Base/Collision/CollisionHandling/imstkVirtualCouplingCH.h

Base/Collision/imstkInteractionPair.cpp

Base/Collision/imstkInteractionPair.h

Base/Scene/imstkCollisionGraph.cpp

Base/Scene/imstkCollisionGraph.h

Base/SimulationManager/imstkSceneManager.cpp

Examples/Sandbox/main.cpp