- Disable generation of core file and stacktrace when running this testcase, which would
   otherwise mark the whole testsuite as failed.


mysql-test/mysql-test-run.pl:
  Allow --skip-core-file to be specified in master.opt file, which will turn
  off the default behaviour to generate core file.
  Remove the option --exit-info from being passed to myslqd when it's started. If used 
  it will just overwrite all the options for skip-stack-trace etc.
mysql-test/t/disabled.def:
  Enable crash_commit_before
mysql-test/t/crash_commit_before-master.opt:
  Run crash_commit_before test case without core file and stack trace.