Add doxygen macro override for Set/GetSmartPointerMacro

This is necessary so that the classes that use the
`Set/GetSmartPointerMacro` get documented properly with doxygen.

Utilities/Doxygen/doxyfile.in

@@ -136,6 +136,10 @@ PREDEFINED  = "vtkSetMacro(name,type)= \
                  virtual void Set##name (type*);" \
               "vtkGetObjectMacro(name,type)= \
                  virtual type *Get##name ();" \
+              "vtkSetSmartPointerMacro(name,type)= \
+                 virtual void Set##name (type*);" \
+              "vtkGetSmartPointerMacro(name,type)= \
+                 virtual type *Get##name ();" \
               "vtkBooleanMacro(name,type)= \
                  virtual void name##On (); \
                  virtual void name##Off ();" \