- Enable main.mysql_upgrade.test
- Record result file according to latest trunk.
- Divide main.mysql_upgrade test case into four tests
  main.mysql_upgrade.test
  main.mysql_upgrade_options.test
  main.mysql_upgrade_grant.test
  main.ps_sys_upgrade.test
- Mark main.mysql_upgrade_options and main.ps_sys_upgrade
  as big test. Add 60 min timeout values for these tests.
- Create on disk tables instead of temporary tables from
  backup_tables_priv_and_users.inc to handle server restarts.