OSD_MAllocHook.cxx fails to compile with "atol not found error"

This happens with gcc 4.6.0 for me.
atol is defined in , which is not included in OSD_MAllocHook.cxx or its headers. This small patch makes that inclusion.

diff -upr OpenCASCADE-6.5.1.orig/ros/src/OSD/OSD_MAllocHook.cxx OpenCASCADE-6.5.1/ros/src/OSD/OSD_MAllocHook.cxx
--- OpenCASCADE-6.5.1.orig/ros/src/OSD/OSD_MAllocHook.cxx 2011-05-19 06:24:52.000000000 -0500
+++ OpenCASCADE-6.5.1/ros/src/OSD/OSD_MAllocHook.cxx 2011-09-06 20:19:40.087027436 -0500
@@ -4,6 +4,7 @@
// Copyright: Open CASCADE S.A.S. 2011

#include
+#include

#ifndef WNT
#if !defined __STDC_LIMIT_MACROS