Last bunch of I/O changes to alloz Lazy_kernel to pass the kernel-I/O test-suite.

Cartesian_kernel/include/CGAL/Cartesian/Iso_rectangle_2.h

@@ -17,7 +17,7 @@
 //
 // $URL$
 // $Id$
-// 
+//
 //
 // Author(s)     : Andreas Fabri, Herve Bronnimann
 

Cartesian_kernel/include/CGAL/Cartesian/Ray_3.h

@@ -64,7 +64,6 @@ public:
   bool        operator==(const RayC3 &r) const;
   bool        operator!=(const RayC3 &r) const;
 
-  const Point_3 &   start() const;
   const Point_3 &   source() const
   {
       return get(base).e0;
@@ -103,14 +102,6 @@ RayC3<R>::operator!=(const RayC3<R> &r) const
   return !(*this == r);
 }
 
-template < class R >
-inline
-const typename RayC3<R>::Point_3 &
-RayC3<R>::start() const
-{
-  return source();
-}
-
 template < class R >
 CGAL_KERNEL_INLINE
 typename RayC3<R>::Point_3