Move downloader client stub connection to buildPendingDownloadIntent

...which is called by the Fragment's onResume(). Can't put it in the Activity's onResume because the client stub isn't created yet there.
Fix #16: Crash after searching for waterfall by name or hike & switching to Map tab

Don't bother trying to add the searched-for location to the map, or compare a returned waterfall's distance to it, if it's not a location search (as indicated by a null returned by getOriginAddress - that could be better). Formalize a couple other methods into the OnLocationQueryListener interface.