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

[Leo White]

> Would it make sense to issuing warnings in the case of shadowing the
> Pervasives module? 

Possibly, although that would prevent (or at least hinder) delibrate shadowings (as opposed to
accidental conflicts).

> Also, what happens if I have a Pervasive module in my project? Would that be opened in each module by default?

If you mean a module called simply "pervasives.ml", then I think that
this would be shadowed by the pervasives in the standard library. If you
mean a module called "foo-pervasives.ml" (for a package foo), then it
would only be opened automatically by files that included an

    open namespace Foo

statement. This includes other files within the foo package.