[geo] provide more flexible Spatial controls (#4032)

Before this PR the only way to query lat/long is in the shape of 2
columns that contains lat and long.

Now we're adding 2 more options:
* a single column that has lat and long with a delimiter in between
* support for geohashes - geohashes are cool

tests/druid_func_tests.py

@@ -200,7 +200,7 @@ class DruidFuncTestCase(unittest.TestCase):
         client.query_builder.last_query.query_dict = {'mock': 0}
         # client.topn is called twice
         ds.run_query(
-            groupby, metrics, None, from_dttm, to_dttm, row_limit=100,
+            groupby, metrics, None, from_dttm, to_dttm, timeseries_limit=100,
             client=client, order_desc=True, filter=[],
         )
         self.assertEqual(2, len(client.topn.call_args_list))