ENH:  Added files and unit tests in VTK/Graphics for Matlab and Gnu R integration with VTK.  Added new advanced CMake options VTK_USE_MATLAB_MEX and VTK_USE_GNU_R to enable builds with Matlab and R.  Building the integration code requires a Matlab installation or an installation of GNU R compiled from source.  The integration files will be compiled with the vtkGraphics library.  Unit tests are located in VTK/Graphics/Testing/Cxx.  Python examples are located in VTK/Examples/Infovis/Python.