Merge pull request #495 in ZP/z-push from bugfix/ZP-1182-logauthfail-doesn-t-log-into-z-push-error.log to develop

* commit '159c6ba7':
  ZP-1182 Check all loglevels bitwise.
  ZP-1182 Also log WARN messages into the error log.
  ZP-1182 Remove logging into the error log as messages for the error log file are also written by afterlog().