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)