Added --restart-cleanup option
drop-on-restart.inc:
  DROP commands to cleanup on restart
  new file
mysqltest.c:
  Added option --include=<sql-file>


client/mysqltest.c:
  Added option --include=<sql-file>
mysql-test/include/drop-on-restart.inc:
  DROP commands to cleanup on restart
mysql-test/mysql-test-run.pl:
  Added --restart-cleanup option