Add concept of surface local geometric estimator. Update normal estimators. Concept checking models.
Add note in concept CSurfaceLocalGeometricEstimator
Make concept CSurfaceLocalGeometricEstimator DefaultConstructible,CopyConstructible and Assignable. Update models of this concept. Fix little bugs in Counted*PtrOr*Ptr. Add == and != operators to CountedPtr and CowPtr.
Forgotten test file