Reverse geocoding: Add entire location object if latlng is not in expected format

I had a problem where I needed to specify a spatial reference when reverse geocoding.
The service takes location in either commaseparated format, or as a JSON point like this:

```{ 
"x": 10,
"y": 20,
"spatialReference": {
    "wkid": 3857
}
}```

I modified the `reverse` function to use the entire `latlng` object as `location` if the `.lat` or `.lng` properties are missing. This way I can explicitly set the spatial reference.