[fpc-pascal] Namespaces Support

[Marco van de Voort]

In our previous episode, Fabr?cio Srdic said:
> > used in Java and .NET as either languages don't have "units".
> > Adding "features" just because "enterpise-class dev platforms" have them
> > is more marketing move, than actual technical need.
> >
> 
> We can't nest units to form a hierarchical content. With namespaces, we
> can.

Yes. But that doesn't need renaming all existing units. It is that part that
I think that is excessive.

Embarcadero did it probably to keep their hands free for some long term VCL
phase-out (IOW that they wouldn't have to rename FM to avoid VCL names).

We don't have any major such problems, and thus renaming everything is a bit
draconical to me. At least till we really have a reason to do so.

> Furthermore, namespaces can be used to disambiguate identifiers with
> the same name, eliminating the need to prefix our identifiers.

That is the main reason why it is added to so many languages;

BUT, Unit based Pascal never had that problem, since units already have
their own namespace.

Namespaces are only for pseudo hierarchical disambiguation of unit names in
Pascal.