Merge branch 'refactoring' into 'master'

.gitattributes

.gitignore

Assembler/Assembler.cpp

Assembler/Assembler.h

Assembler/UnitTests/AssemblerSpec.cpp

Assembler/UnitTests/CMakeLists.txt

Base/Collision/CMakeLists.txt

Base/Collision/CollisionData/imstkCollisionData.h

.../Collision/CollisionDetection/imstkCollisionDetection.cpp

Base/Collision/CollisionDetection/imstkCollisionDetection.h

Base/Collision/CollisionDetection/imstkMeshToMeshCD.cpp

Base/Collision/CollisionDetection/imstkMeshToMeshCD.h

Base/Collision/CollisionDetection/imstkPlaneToSphereCD.cpp

Base/Collision/CollisionDetection/imstkPlaneToSphereCD.h

Base/Collision/CollisionDetection/imstkSphereToSphereCD.cpp

Base/Collision/CollisionDetection/imstkSphereToSphereCD.h

Base/Collision/CollisionHandling/imstkCollisionHandling.cpp

Base/Collision/CollisionHandling/imstkCollisionHandling.h

...Collision/CollisionHandling/imstkPenaltyMeshToRigidCH.cpp

Base/Collision/CollisionHandling/imstkPenaltyMeshToRigidCH.h