Move <CGAL/Testsuite/use.h> to <CGAL/use.h> (in the Installation package)

That is a followup to the following commit:
  | ------------------------------------------------------------------------
  | r71090 | pmoeller | 2012-08-07 13:04:32 +0200 (Tue, 07 Aug 2012) | 6 lines
  | Changed paths:
  |    M /branches/next/Alpha_shapes_2/include/CGAL/Alpha_shape_2.h
  |    M /branches/next/Circulator/include/CGAL/circulator.h
  |    M /branches/next/Convex_decomposition_3/include/CGAL/Convex_decomposition_3/Reflex_vertex_searcher.h
  |    M /branches/next/Intersections_3/test/Intersections_3/bbox_other_do_intersect_test.cpp
  |    M /branches/next/Kernel_d/include/CGAL/Cartesian_d.h
  |    M /branches/next/Mesh_3/include/CGAL/IO/File_medit.h
  |    M /branches/next/Mesh_3/include/CGAL/Mesh_cell_criteria_3.h
  |    M /branches/next/Mesh_3/include/CGAL/Mesh_edge_criteria_3.h
  |    M /branches/next/Mesh_3/include/CGAL/Mesh_facet_criteria_3.h
  |    M /branches/next/Mesh_3/include/CGAL/make_mesh_3.h
  |    M /branches/next/Nef_2/include/CGAL/Bounded_kernel.h
  |    M /branches/next/Nef_2/include/CGAL/Nef_polyhedron_2.h
  |    M /branches/next/Nef_3/include/CGAL/Nef_3/ID_support_handler.h
  |    M /branches/next/Nef_3/include/CGAL/Nef_3/Infimaximal_box.h
  |    M /branches/next/Nef_3/include/CGAL/Nef_3/vertex_cycle_to_nef_3.h
  |    M /branches/next/Nef_3/include/CGAL/Nef_polyhedron_3.h
  |    M /branches/next/Nef_3/test/Nef_3/nef_union_error_llvm.cpp
  |    M /branches/next/Nef_S2/include/CGAL/Nef_S2/SM_overlayer.h
  |    M /branches/next/OpenNL/include/CGAL/OpenNL/blas.h
  |    M /branches/next/Periodic_3_triangulation_3/include/CGAL/Periodic_3_triangulation_3.h
  |    M /branches/next/Point_set_processing_3/include/CGAL/mst_orient_normals.h
  |    M /branches/next/QP_solver/include/CGAL/QP_solver/QP_functions_impl.h
  |    M /branches/next/STL_Extension/include/CGAL/iterator.h
  |    M /branches/next/Segment_Delaunay_graph_2/include/CGAL/Segment_Delaunay_graph_simple_site_2.h
  |    M /branches/next/Subdivision_method_3/include/CGAL/Polyhedron_decorator_3.h
  |    M /branches/next/Subdivision_method_3/include/CGAL/Subdivision_mask_3.h
  |    M /branches/next/Surface_mesher/include/CGAL/Surface_mesh_default_criteria_3.h
  |    M /branches/next/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Adaptation_traits_functors.h
  |    M /branches/next/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Default_site_inserters.h
  |    M /branches/next/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Default_site_removers.h
  | 
  | WARNFIX: Silence a good part of unused variable/parameter warnings.
  | 
  | Wextra results in a dreadful wall of yellow in the test-suite and is
  | scary when using CGAL. Reduce some of the noise by silencing the
  | obvious cases with CGAL_USE or comments.
  | 
  | ------------------------------------------------------------------------

The reason is that everything from CGAL/Testsuite/ is removed in public
releases (that was discussed at a CGAL developers meetings, long ago). That
means that r71090 introduced compilation errors undetectable by the tests
of internal releases. I hope that the minutes of that developers meeting
say that I was against the removal of headers between internal and public
releases!  -- Laurent Rineau

Circulator/include/CGAL/circulator.h

@@ -30,7 +30,7 @@
 #include <functional>
 #include <iterator>
 #include <CGAL/circulator_bases.h>
-#include <CGAL/Testsuite/use.h>
+#include <CGAL/use.h>
 
 // These are name redefinitions for backwards compatibility
 // with the pre iterator-traits style adaptors.

Installation/include/CGAL/use.h

@@ -0,0 +1,34 @@
+// Copyright (c) 2007   INRIA Sophia-Antipolis (France).
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation; either version 3 of the License,
+// or (at your option) any later version.
+//
+// Licensees holding a valid commercial license may use this file in
+// accordance with the commercial license agreement provided with the software.
+//
+// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+//
+// $URL$
+// $Id$
+//
+// Author(s)     : Sylvain Pion
+
+#ifndef CGAL_USE_H
+#define CGAL_USE_H
+
+namespace CGAL { namespace internal {
+
+template < typename T > inline
+void use(const T&) {}
+
+} }
+
+// CGAL_USE() is a macro which aims at removing "variable is unused" warnings.
+
+#define CGAL_USE(x) ::CGAL::internal::use(x)
+
+#endif // CGAL_USE_H

Point_set_processing_3/include/CGAL/mst_orient_normals.h

@@ -28,7 +28,7 @@
 #include <CGAL/Index_property_map.h>
 #include <CGAL/Memory_sizer.h>
 #include <CGAL/point_set_processing_assertions.h>
-#include <CGAL/Testsuite/use.h>
+#include <CGAL/use.h>
 
 #include <iterator>
 #include <list>

STL_Extension/include/CGAL/iterator.h

@@ -29,7 +29,7 @@
 
 #include <CGAL/circulator.h>
 #include <CGAL/assertions.h>
-#include <CGAL/Testsuite/use.h>
+#include <CGAL/use.h>
 #include <vector>
 #include <map>
 #include <boost/type_traits.hpp>

Testsuite/include/CGAL/Testsuite/use.h

@@ -20,15 +20,9 @@
 #ifndef CGAL_TESTSUITE_USE_H
 #define CGAL_TESTSUITE_USE_H
 
-namespace CGAL { namespace internal {
+// This is a wrapper file, for backward compatibility.
+// The macro CGAL_USE is now defined in <CGAL/use.h>
 
-template < typename T > inline
+#include <CGAL/use.h>
-void use(const T&) {}
-
-} }
-
-// CGAL_USE() is a macro which aims at removing "variable is unused" warnings.
-
-#define CGAL_USE(x) ::CGAL::internal::use(x)
 
 #endif // CGAL_TESTSUITE_USE_H