not needed by the tescases. This will save test time for those testcases
that does not need cluster, but need a restart, as they dont have to wait
the extra time it would take for cluster to restart. It will also save
time for other testcases, as cluster does not 
need to be contacted for each table to be dropped or created.
Backport from 5.1


mysql-test/lib/mtr_cases.pl:
  Mark all test cases where name contains "ndb" as ndbcluster needed
mysql-test/lib/mtr_match.pl:
  Add mtr_match_substring function
mysql-test/lib/mtr_stress.pl:
  Extre param to mysqld_start
mysql-test/mysql-test-run.pl:
  Only start ndbcluster for testcases that needs it.