[ocaml-platform] Changes to my previous proposal for namespaces

[Leo White]

> That's why I added "even if there is no conflict".  In most of the cases, there is no conflict, and in that case, the
> order does not matter.  With Leo's proposal, an alias in foo.mlpath would be resolved only using -I flags before "-I
> foo.mlpath".

I think that shadowing (i.e. delibrate conflicts) between names in the
search path will be more common once those names are not tied to the
unique module name. So I think that it will be important for packages to
specify the dependencies of their path files even without aliases.

Currently, shadowing a compilation unit "foo.cmi" involves creating
another unit called "foo.cmi". Since these have the same name they can't
be linked within the same program, which limits the usefulness of this
kind of shadowing. With search path files this is no longer the case.