Fix many tests and handle ownership issues involved

with Cartodbfy being invoked by schema triggers. Some
issues with regclass interpretation in tests still remain.
Some issues with slightly different behavior to old version
remain. Some issues with error messages / notification messages
changing a little still remain.

sql/test_ddl_triggers.sql

@@ -10,6 +10,7 @@ create schema c;
 
 SELECT CDB_SetUserQuotaInBytes('c', 0);
 
+DROP USER IF EXISTS cartodb_postgresql_unpriv_user;
 CREATE USER cartodb_postgresql_unpriv_user;
 GRANT ALL ON SCHEMA c to cartodb_postgresql_unpriv_user;
 SET SESSION AUTHORIZATION 'cartodb_postgresql_unpriv_user';

sql/test_setup.sql

@@ -7,4 +7,4 @@ RETURNS void AS $$
 BEGIN
   RAISE NOTICE 'cdb_invalidate_varnish(%) called', table_name;
 END;
-$$ LANGUAGE 'plpgsql';
+$$ LANGUAGE 'plpgsql';