Added example which exposes the difference between building with Make
and building with Ocamlbuild.

The executable will throw an exception when built with Ocamlbuild,
because id_piqi_ext will not be linked in.
Quick fix to enable building with Ocamlbuild when multi-format option of
piqic-ocaml is used
Merge branch 'runtime_exc'

Conflicts:
	piqic-ocaml/piqic_common.ml