[Geojson] clarification on Feature id

[Keith Jenkins]

On Sat, Mar 15, 2008 at 5:54 PM, Christopher Schmidt
<crschmidt at metacarta.com> wrote:
>  "id" isn't part of the spec. So, it's definitely not required, though it
>  probably makes sense to put it there, and most implementations that I've
>  seen that have such a thing will do so. However, I've always seen it as
>  reasonably common sense, and not worked it into the spec (though I
>  wouldn't have a problem with making it recommended).

I think it makes sense to recommend it, and if so, also to mention it
in the spec as a special element that can exist directly within the
Feature object, rather than being relegated to the properties object.

Cheers,
Keith