Fix for bug #418

Increased skygw_query_type_t to 16 bits, and corrected the way how those bit fields are checked.
Added tests for cases where autocommit is disabled and corrected old tests.

server/modules/routing/readwritesplit/test/test_implicit_commit3.sql

@@ -1,6 +1,6 @@
 USE test;
 DROP TABLE IF EXISTS T1;
-SET autocommit=0;
+SET autocommit=1;
 BEGIN;
 CREATE TABLE T1 (id integer); -- implicit commit
 SELECT (@@server_id) INTO @a;