- Don't give mysqld the --log-bin argument if .opt file
  contains --skip-log-bin
- Enable flush2 test


mysql-test/mysql-test-run.pl:
  Don't give mysqld the --log-bin argument if .opt file contains --skip-log-bin 
  Don't pass mysqld --binlog-format=s if --skip-log-bin
mysql-test/t/disabled.def:
  Enable flush2
mysql-test/t/flush2-master.opt:
  Use --skip-log-bin in flush2 to test flush without bin logging