* a dedicated test for wsrep_retry_autocommit
* some galera_toi_* tests were only passing because wsrep_retry_autocommit
  was in effect. The tests were changed to do not use autocommit
* higher timeout values in galera_2nodes.cnf , galera_3nodes.cnf
Signed-off-by: Sachin Setiya <sachin.setiya@mariadb.com>