Log Message:
Updated package to latest version, 6.16. Changes include:
* [28 Apr 16] Fixed problems of compatibility with previous versions of
  ocaml.
* [23 Jan 16] Fixed bug on optional types (ocaml 4.02).
* [15 Jan 16] Fixed bug on methods wrongly interpreted as vals.
* [05 Jan 16] Updated for ocaml trunk 4.03.0
  (git version be2a7e2f830911b331657b8cfa462f5219dfec5b)
* [26 Nov 15] Updated again for ocaml trunk current version (4.03.0).
* [23 Sep 15] Updated for ocaml trunk current version (4.03.0).