Do for Point_d the same as for Vector_d

Kernel_d/include/CGAL/Kernel_d/Point_d.h

@@ -80,7 +80,12 @@ public:
 
   Point_d(const Self &p) : Base(p) {}
   Point_d(const Base& p) : Base(p) {}
- 
+
+#ifndef CGAL_CFG_NO_CPP0X_DELETED_AND_DEFAULT_FUNCTIONS
+  Self&
+  operator=(const Self& v)=default;
+#endif
+  
   Vector_d<R> operator-(const Origin& o) const 
   { return Base::operator-(o); }
   Vector_d<R> operator-(const Self& q) const