[SMI] patch

[Michael Alexander]

had to patch it in order to compile SMI with GCC 4.8, will log it in Cbc - 

-- Michael

--- CbcEventHandler.hpp.save 2013-11-26 14:37:44.520438789 +0100
+++ CbcEventHandler.hpp 2013-11-26 14:36:57.288290366 +0100
@@ -6,6 +6,8 @@
 #ifndef CbcEventHandler_H
 #define CbcEventHandler_H
 
+// MA GCC 4.6+ C++ STL headers missing cstddef
+#include <cstddef>
 
 /*! \file CbcEventHandler.hpp
     \brief Event handling for cbc