OVERRIDDEN BY 'DELETE' CMD

Postfix on two failures:
- mysql failed with the error that --build-completion-hash didn't exist
  Added "have_mysql_dbug.inc" to skip the test when mysql
  is compiled without --build-completion-hash.

- Valgrind failure of rpl_no_gtid_delete_memory_table_after_start_server
  Because valgrind test is very slow, it spends a long time to restart
  server. That caused slave IO reconnect timeout.

  To fix it, slave is stopped before restarting the server and it is
  restarted after the server is restared.