[Therion] Patch for VTK6 support

Hi folks, Attached is a patch to make therion (in particular loch) work with vtk6. We're now using this patch in the Debian package, since Debian is switching from vtk5 to vtk6. My understanding is that loch currently uses compatibility functions which support vtk4-style code, and that the code changes should be compatible with vtk5 too. That's based on this page (I didn't test with vtk5): http://www.vtk.org/Wiki/VTK/VTK_6_Migration/Replacement_of_SetInput Cheers, Olly