x11-toolkits/ocaml-lablgtk2: the port had been updated and improved (+)

- Update to the latest version 2.18.13
- Convert that abominable `post-patch' target to static patch and
  leave only parts of it which matter (visible in the build log)
- Fix a typo in the `src/Makefile' to prevent `sourceView2Enums.ml'
  from being removed as intermediate file

Submitted by:	naddy (typo fix for gmake 4.4 update)
Reported by:	portscout