updated editor's draft of the Geolocation API specification in preparation for the Last Call transition

Hi,
In preparation of the Last Call transition, I've fixed the issues that were
raised during the last few days:

- Implemented Alissa's suggestion about using "express permission"
everywhere in the Privacy section
- Updated the IDL following the discussion between Marcin and Cameron.

The diff is here:

http://dev.w3.org/cvsweb/geo/api/spec-source.html.diff?r1=1.61&r2=1.62&f=h


I will shortly add these issues in our tracker, as well.

Thanks,
Andrei