REFAC: Use forward declerations where possible

Examples/BoneShaving/BoneShavingExample.cpp

Examples/CameraController/CameraControllerExample.cpp

...etection/ManualCDWithOctree/ManualCDWithOctreeExample.cpp

Examples/CreateEnclosingMesh/CreateEnclosingMesh.cpp

Examples/DebugRendering/DebugRenderingExample.cpp

Examples/DeformableBody/DeformableBodyExample.cpp

Examples/GeometryProcessing/GeometryProcessingExample.cpp

Examples/GeometryTransforms/GeometryTransformsExample.cpp

Examples/Graph/GraphExample.cpp

Examples/LineMesh/LineMeshExample.cpp

Examples/MultipleScenes/multipleScenes.cpp

Examples/ObjectController/ObjectControllerExample.cpp

...ectControllerDummyClient/ObjectCtrlDummyClientExample.cpp

Examples/Octree/OctreeExample.cpp

Examples/PBD/PBDCloth/pbdClothExample.cpp

...ionMultipleObjects/PBDCollisionMultipleObjectsExample.cpp

...BD/PBDCollisionOneObject/PBDCollisionOneObjectExample.cpp

...ples/PBD/PBDCollisionStairs/PBDCollisionStairsExample.cpp

Examples/PBD/PBDDeformableObject/PBD3DDeformableObject.cpp

Examples/PBD/PBDFluids/PBDFluidsExample.cpp