add comments

CGAL_ImageIO/src/CGAL_ImageIO/analyze_impl.h

@@ -52,7 +52,7 @@
 #define DT_RGB                  128 /* */
 #define DT_ALL                  255 /* */
 
-#include <string>
+#include <cstring>
 
 struct header_key                       /*      header_key       */
     {                                           /* off + size*/

Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h

@@ -149,6 +149,9 @@ namespace CGAL {
     {
     public:
 
+        // Workaround for a bug in g++4.4 in ADL for function next:
+        // we provide the types needed for std::iterator_traits<Surface_mesh::halfedge_index>,
+        // although this descriptor is not an iterator.
         typedef void iterator_category;
         typedef void value_type;
         typedef void difference_type;