Add Construct_point_2/3 to the concepts of triangulation traits

-- TriangulationTraits_2 requires Point_2 construct_point_2(Point_2)
-- RegularTriangulationTraits_2 requires Point_2 construct_point_2(Weighted_point_2)
-- TriangulationTraits_3 requires Point_3 construct_point_3(Point_3)
-- RegularTriangulationTraits_3 requires Point_3 construct_point_3(Weighted_point_3)

Triangulation_2/doc/Triangulation_2/Concepts/RegularTriangulationTraits_2.h

@@ -66,6 +66,15 @@ which is the degenerate power test for weighted points
 */ 
 typedef unspecified_type Power_side_of_oriented_power_circle_2; 
 
+/*!
+A constructor type,
+model of `Kernel::ConstructPoint_2`.
+The `operator()` extracts the bare point from a weighted point.
+
+`Point_2 operator() ( Weighted_point_2 p);`
+*/
+typedef unspecified_type Construct_point_2;
+
 /// @}
 
 /// \name Optional Types
@@ -147,6 +156,11 @@ Compare_power_distance_2 compare_power_distance_2_object();
 
 /*!
 
+*/
+Construct_point_2 construct_point_2_object();
+
+/*!
+
 */ 
 Construct_weighted_circumcenter_2 
 construct_weighted_circumcenter_2_object(); 

Triangulation_2/doc/Triangulation_2/Concepts/TriangulationTraits_2.h

@@ -40,6 +40,21 @@ The triangle type.
 */ 
 typedef unspecified_type Triangle_2; 
 
+/*!
+A function object to construct a `Point_2`.
+
+Provides:
+
+`Point_2 operator()(Point_2 p)`,
+
+which simply returns p.
+
+\note This constructor is necessary because `Regular_triangulation_2`
+inherits `Triangulation_2` and will provide an overload of `Construct_point_2`
+that strips the weight from a weighted point.
+*/
+typedef unspecified_type Construct_point_2;
+
 /*!
 A function object to construct a `Segment_2`. 
 
@@ -189,6 +204,11 @@ TriangulationTraits_2 operator=(TriangulationTraits_2 gtr);
 
 /*!
 
+*/
+Construct_point_2 construct_point_2_object();
+
+/*!
+
 */ 
 Construct_segment_2 construct_segment_2_object(); 
 

Triangulation_3/doc/Triangulation_3/Concepts/RegularTriangulationTraits_3.h

@@ -141,7 +141,16 @@ typedef unspecified_type Compare_power_distance_3;
 
 /*!
 A constructor type,
-model of `ConstructWeightedCircumcenter_3`.
+model of `Kernel::ConstructPoint_3`.
+The `operator()` extracts the bare point from a weighted point.
+
+`Point_3 operator() ( Weighted_point_3 p);`
+*/
+typedef unspecified_type Construct_point_3;
+
+/*!
+A constructor type,
+model of `Kernel::ConstructWeightedCircumcenter_3`.
 The `operator()` constructs the bare point 
 which is the center of the smallest orthogonal sphere to the input 
 weighted points. 
@@ -217,6 +226,10 @@ Power_side_of_oriented_power_sphere_3 power_side_of_oriented_power_sphere_3_obje
 */
 Compare_power_distance_3 compare_power_distance_3_object();
 
+/*!
+
+*/
+Construct_point_3 construct_point_3_object();
 
 /// @}
 

Triangulation_3/doc/Triangulation_3/Concepts/TriangulationTraits_3.h

@@ -46,6 +46,19 @@ The triangle type.
 */ 
 typedef unspecified_type Triangle_3; 
 
+/*!
+A constructor object that must provide the function operator
+
+`Point_3 operator()(Point_3 p)`,
+
+which simply returns p.
+
+\note This constructor is necessary because `Regular_triangulation_3`
+inherits `Triangulation_3` and will provide an overload of `Construct_point_3`
+that strips the weight from a weighted point.
+*/
+typedef unspecified_type Construct_point_3;
+
 /*!
 A constructor object that must provide the function operator 
 
@@ -129,21 +142,26 @@ Triangulation_traits_3(const Triangulation_traits_3 & tr);
 
 /*!
 
+*/
+Construct_point_3 construct_point_3_object();
+
+/*!
+
+*/
+Construct_segment_3 construct_segment_3_object();
+
+/*!
+
+*/
+Construct_triangle_3 construct_triangle_3_object();
+
+/*!
+
 */ 
 Construct_tetrahedron_3 construct_tetrahedron_3_object(); 
 
 /*!
 
-*/ 
-Construct_triangle_3 construct_triangle_3_object(); 
-
-/*!
-
-*/ 
-Construct_segment_3 construct_segment_3_object(); 
-
-/*!
-
 */ 
 Compare_xyz_3 compare_xyz_3_object();