WIP bump vtk's expat

see github branch where I: copy over lib/.h and lib/.c into VTK/TP/expat/vtkexpat copy over ./expat_config.cmake into VTK/TP/expat/vtkexpat chmod -x the same cmake file edit vtkexpat/cmakelist.txt to compile the new source files and configure the .cmake file into a .h remove the amigaconfig file on a shared lib mac build, compile and test -> there are no test failures

todo: whitespace check problems cleanup the config files (consolidate/remove winconfig, watcomconfig, macconfig, expat*Config.in) update mangling verify install works, use system works, windows and linux work search for important updates we want to preserve from vtk's expat and upstream them or put in our fork