Bump GeoModelVersion down! to 6.6.0. Also use const were appropriate after Rui...

Bump GeoModelVersion down! to 6.6.0. Also, Rui implements a change to prefer virtual functions to dynamic casts, but no change in functionality or the important user interfaces in the new surface classes. Fully tested with Athena and AthSimulation.

GeoModelCore/GeoModelKernel/GeoModelKernel/GeoAnnulusSurface.h

@@ -76,6 +76,7 @@ class GeoAnnulusSurface : public GeoVSurfaceShape
 
       void exec (GeoShapeAction *action) const override final;
 
+      virtual bool isOnSurface (const double Px, const double Py, const double Pz, const GeoTrf::Transform3D & trans) const override final;
     
     protected:
 
@@ -90,4 +91,4 @@ class GeoAnnulusSurface : public GeoVSurfaceShape
       double m_phi{2*M_PI};
 };
 
-#endif
\ No newline at end of file
+#endif