Fix missing definitions for Nef_2

Author: GilesBathgate

Nef_2/include/CGAL/Nef_2/PM_const_decorator.h

@@ -21,6 +21,7 @@
 #include <string>
 #include <list>
 #include <sstream>
+#include <CGAL/Nef_2/Object_handle.h>
 #include <CGAL/Nef_2/Object_index.h>
 #include <CGAL/Nef_2/iterator_tools.h>
 #undef CGAL_NEF_DEBUG
@@ -158,6 +159,12 @@ typedef typename HDS::Face_handle             Face_handle;
 typedef typename HDS::Face_const_handle       Face_const_handle;
 typedef typename HDS::Face_const_iterator     Face_const_iterator;
 
+typedef typename CGAL::Type_pack<Vertex_handle,   Vertex_const_handle,
+                                 Halfedge_handle, Halfedge_const_handle,
+                                 Face_handle,     Face_const_handle>
+                                                  Object;
+
+typedef typename CGAL::Object_handle<Object> Object_handle;
 
 /*{\Mtext Local types are handles, iterators and circulators of the
 following kind: |Vertex_const_handle|,

Nef_2/include/CGAL/Nef_2/PM_decorator.h

@@ -69,8 +69,9 @@ decorator to examine and modify a plane map. |\Mvar| inherits from
   typedef typename Base::Isolated_vertex_const_iterator Isolated_vertex_const_iterator;
   typedef typename Base::Point_const_iterator Point_const_iterator;
   typedef typename Base::Mark Mark;
-typedef typename Base::Point Point;
-typedef typename Base::GenPtr GenPtr;
+  typedef typename Base::Point Point;
+  typedef typename Base::GenPtr GenPtr;
+  typedef typename Base::Object_handle Object_handle;
 
 /*{\Mtext Local types are handles, iterators and circulators of the following
 kind: |Vertex_handle|, |Vertex_iterator|, |Halfedge_handle|,

Nef_2/include/CGAL/Nef_2/PM_point_locator.h

@@ -104,7 +104,7 @@ class PM_naive_point_locator : public PM_decorator_ {
   |Halfedge_const_handle|, |Halfedge_const_iterator|, |Face_const_handle|,
   |Face_const_iterator|.}*/
 
-  typedef CGAL::Object_handle Object_handle;
+  typedef typename PM_decorator_::Object_handle Object_handle;
   /*{\Mtypemember a generic handle to an object of the underlying plane
   map. The kind of the object |(vertex, halfedge,face)| can be determined and
   the object assigned by the three functions:\\