message: ENH: change toleranace for ray/box intersect
  Use floating_point_limits< T >::epsilon() for the default
  tolerance used in ray/box intersection tests.
diff: @@ -173,7 +173,7 @@ inline bool intersect_ray( const T& x0,
  const T& ymin,
  const T& ymax,
  T& t,
  - T TOL=1.e-9 )
  + T TOL=numerics::floating_point_limits<T>::epsilon() )
  {
  AXOM_STATIC_ASSERT( std::is_floating_point< T >::value );
  @@ -222,7 +222,7 @@ inline bool intersect_ray( const T& x0,
  const T& zmin,
  const T& zmax,
  T& t,
  - T TOL=1.e-9)
  + T TOL=numerics::floating_point_limits<T>::epsilon() )
  {
  AXOM_STATIC_ASSERT( std::is_floating_point< T >::value );
  @@ -258,7 +258,7 @@ template < typename T, int DIM >
  inline bool intersect_ray( const primal::Ray< T,DIM > & R,
  const primal::BoundingBox< T,DIM > & bb,
  primal::Point< T,DIM > & ip,
  - T TOL=1.e-9 )
  + T TOL=numerics::floating_point_limits<T>::epsilon() )
  {
  AXOM_STATIC_ASSERT( std::is_floating_point< T >::value );
  