When set log to console, if fmt.Print larger than 1K
  the output buffer will be truncate. This problem will be
  trigger when set log to stdout, beego and soar both print their
  output into stdout, and this may come into confusing status in
  mac os.

  For fixing this problem, we only allow set log to file not.
  SOAR never write SQL suggest into log. Only developer should be
  concern about log, common user have no need of looking up log.

  -check-config will check
  * YAML format
  * OnlineDSN connection
  * TestDSN connection

  add doc for blacklist config

  1. fix -config arg parse bug
  2. code & comment lint