Exposes geocoder providers in public geocoder functions

Add config function in postgres explicitly to get MapzenGeocoderConfig.
Bump versions for client and server APIs. New MapzenGeocoderConfig
included to be able to use current QuotaServices with non-configured
users.

client/old_versions/cdb_dataservices_client--0.7.0--0.6.0.sql

@@ -0,0 +1,5 @@
+--DO NOT MODIFY THIS FILE, IT IS GENERATED AUTOMATICALLY FROM SOURCES
+-- Complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "ALTER EXTENSION cdb_dataservices_client UPDATE TO '0.6.0'" to load this file. \quit
+DROP FUNCTION IF EXISTS cdb_dataservices_client._obs_getmeasurebyid (text, text, text, text);
+DROP FUNCTION IF EXISTS cdb_dataservices_client.obs_getmeasurebyid (text, text, text, text);