[Import-SIG] Is ".ns" really the right extension?

["Martin v. Löwis"]

> I don't particularly like .contrib, and I saw in a followup that someone
> proposed .pyp.  I'd be fine with that, but if you want something more
> descriptive (i.e. longer), then .portion works for me.

I'd rather avoid something longer. It's a long-time convention at least
on Windows to use no more than three characters for file extensions.

Regards,
Martin