FIX of VTK 6 configuration for Windows and VS 2010. New Feature: user defined lookup tabled for scalars from vtk files

FIX: fixed a build problem in VTK.cmake. 64 bit operators << of ofstream would otherwise get ambigious with VS2010 WIN 64

FEATURE: allow to load user defined lookup tables for scalar values in mitkSurfaceGLMapper2D.cpp. Scalar data needs to contain a lut in .vtk data file.  (use scalardata->SetLookupTable(yourlut) when saving vtk files)

Hope that this helps someone. I saw a few posts about this in the mailing list archives.