[vtk-developers] Added NewInstance()

[Berk Geveci]

I just added a virtual function called NewInstance to vtkTypeMacro.
NewInstance creates and returns an object of the same type as the
current one. It does not copy any properties. The returned pointer is 
of the same type as the pointer the method was invoked with. This
method should replace all the MakeObject methods scattered through
VTK.

-Berk