Log to stderr if isatty or syslog otherwise
Log to stderr if isatty or syslog otherwise

chen0510566/ach,golems/ach,golems/ach,golems/ach,chen0510566/ach,golems/ach,golems/ach,golems/ach,chen0510566/ach,chen0510566/ach,chen0510566/ach,chen0510566/ach