spec updated

Hello,

I have made two small modifications to the Geolocation API spec:

1. Updated the wording for the watchPosition() method, as suggested by
Alec Berntson:

http://dev.w3.org/geo/api/spec-source.html#watch-position  (see step 2)

2. Added timeouts as proposed in

http://lists.w3.org/Archives/Public/public-geolocation/2008Aug/0013.html

Please let me know if you have any comments.

Thanks,
Andrei