[vtkusers] Which is the actual vtk-version

[Carsten Kübler]

VTK 4.1.1 Nightly build
	SET(VTK_MAJOR_VERSION 4)
	SET(VTK_MINOR_VERSION 1)
	SET(VTK_BUILD_VERSION 1)

http://public.kitware.com/VTK/pdf/file-formats.pdf
	describe the file format of Vtk version 4.2

Carsten