Show stack trace if the return code is not zero.
Add a flag to control the log level to show stacktrace.
Update imosh.
Implement imosh::die and imosh::quiet_die.
Terminate a root process after killing child processes.
Update imosh.
Add a stack trace image to README.
Merge pull request #34 from imos/experimental

Implement imosh::die and imosh::quiet_die.