examples: Add hello-ocaml example.

examples: Add hello-ocaml example.

* gettext-tools/examples/hello-ocaml/INSTALL: New file.
* gettext-tools/examples/hello-ocaml/autogen.sh: New file.
* gettext-tools/examples/hello-ocaml/autoclean.sh: New file.
* gettext-tools/examples/hello-ocaml/dune.in: New file.
* gettext-tools/examples/hello-ocaml/dune-project.in: New file.
* gettext-tools/examples/hello-ocaml/hello.ml.in: New file.
* gettext-tools/examples/hello-ocaml/Makefile.am: New file.
* gettext-tools/examples/hello-ocaml/configure.ac: New file.
* gettext-tools/examples/hello-ocaml/m4/Makefile.am: New file.
* gettext-tools/examples/hello-ocaml/po/LINGUAS: New file.
* gettext-tools/examples/hello-ocaml/po/Makefile.am: New file.
* gettext-tools/examples/Makefile.am (EXAMPLESFILES, EXAMPLESDIRS): Add
hello-ocaml.
* gettext-tools/examples/po/Makefile.am (POTFILES, SMALLPOTS): Update for
hello-ocaml.
(hello-ocaml.pot): New target.
(SMALLPOFILES_FOR_lang): Update for hello-ocaml.
($(srcdir)/../hello-ocaml/po/$(LL).po): New rule.
* gettext-tools/examples/check-examples (func_check__hello_ocaml): New function.
* gettext-tools/examples/README: Mention hello-ocaml.
* gettext-tools/doc/lang-ocaml.texi: Likewise.
* NEWS: Likewise.