[vtkusers] write my own classes in vtk4.0

[Jianlong Zhou]

Hi, vtk users,

I use vtk 4.0 and now want to derive my own classes from vtk classes. In vtk3.2, I can 
put my own derived classes into directory "local". In vtk 4.0, where should I put my own 
class and how to compile it? Thank you very much for your help.

Best regards,
Jianlong