GEOMESA-213 GeoHash corner cases

* GeoHashes now must be inside the rectangle [-180.0, 180.0] by [-90.0, 90.0].
* The top and right corners of the world rectangled are now 'nudged' back in rather than wrapping.
To the point that @anthonyccri made earlier:  It would be useful to test this with GeoServer to see how many requests (if any) we break with these requirements.