Geoloc

A geolocation service.

I don't know if the function and features must be given like this, as parameters.
And all these "logic" must be really in the service ? I think that's good like this but I'm not sur.

Other things, Does this services must have a "remove" function to unbind all created events ?

Thanks to review.
Add a `goog.provide` for that (`ngeo.DecorateGeolocation` really). Not strictly required for `function` type services, but for the sake of consistency with the other ngeo services.