[vtkusers] build error when compiling cvs version

[Arnaud Gelas]

Hi everyone,

I have been trying to compile the cvs version of vtk for the last past 
two days, and I always had the same errors:
http://www.cdash.org/CDash/viewBuildError.php?buildid=294521

I have checked these files are not missing... I guess it is an error in 
the GUISupport/Qt/CMakeLists.txt, some INCLUDE_DIRECTORIES may be missing...
Note that if I comment out the file vtkTreeRingView3.cxx, it is 
compiling without any errors.

Arnaud