Update base ocaml 4.01-trunk

From trunk
        commit cdd43f280062f7d6693eabec6439623ccece6030
        Author: Gabriel Scherer <gabriel.scherer@gmail.com>
        Date:   Sun Jul 21 20:03:52 2013 +0000
To 4.01
        commit 572183501ab011fc6c03e35db8c1fea82214ba13
        Author: Gabriel Scherer <gabriel.scherer@gmail.com>
        Date:   Tue Aug 20 16:02:58 2013 +0000