156195 – please bump PORTREVISION of all ocaml-dependent libraries

Recently, ocaml was updated to 3.12. This has serious impact on all
ocaml-dependent ports, whether library or application.

I would like to have had a ports/UPDATING entry, please add one.

We should consider bumping PORTREVISION for all ocaml-dependent ports, but
at the very least for ocaml-lablgl and ocaml-lablgtk2.  There may be more
fallout elsewhere.

One case study is net/unison232, pav@ forwarded a tinderbox failure to me:

- net/unison232 itself failed after ocaml 3.12 changes.
  I've fixed this with a patch that has gone into unison240 (net/unison)
  upstream (already committed). 

- net/unison232 in default configuration uses ocaml-lablgtk2, which I had
  compiled/installed with the previous unison version, and subsequently failed:

  | ocamlopt -I lwt -I ubase -I +lablgtk2 -c /var/tmp/usr/ports.cvs/net/unison232/work/unison-2.32.52/uigtk2.ml
  | File "/var/tmp/usr/ports.cvs/net/unison232/work/unison-2.32.52/uigtk2.ml", line 1, characters 0-1:
  | Error: /usr/local/lib/ocaml/lablgtk2/gdk.cmi
  | is not a compiled interface
  | gmake: *** [uigtk2.cmx] Error 2

  This can be fixed by recompilation of $LOCALBASE/lib/ocamls/lablgtk2/gdk.cmi
  (in ocaml-lablgtk2), but for the lablgtk2 change to succeed, we need to
  rebuild ocaml-lablgl BEFORE (else ocaml-lablgtk2 fails to configure).

I was tempted to change these two ports myself, but let's rather go for a
complete solution.

Summarized, this is needed to get net/unison232 to compile again after
the ocaml 3.X -> 3.12 update:

- reinstall ocaml-lablgl (please bump PORTREVISION to assist)
- reinstall ocaml-lablgtk2 (please bump PORTREVISION to assist)
- patch unison232 (already committed)

Fix: 

See "Description" section above.