Fix renderCube example. Add header files in charge of loading

Core/Factory.h

Core/Factory.hpp

Core/RenderDelegate.h

Core/SDK.cpp

Core/SDK.h

Core/StaticSceneObject.cpp

Core/ViewerBase.cpp

Core/ViewerBase.h

Examples/renderCube/CMakeLists.txt

Examples/renderCube/main.cpp

Examples/vegaFem/main.cpp

IO/IO.h

IO/IOMesh.cpp

IO/IOMeshAssimpDelegate.cpp

IO/IOMeshDelegate.h

Mesh/SurfaceMesh.cpp

Rendering/OpenGLRenderer.cpp

VTKRendering/VTKMeshRenderDelegate.cpp

VTKRendering/VTKPlaneRenderDelegate.cpp

VTKRendering/VTKRenderDelegate.h