Kurtseifried/secure config and log permissions

All configuration files (e.g. files in /etc/) and all log files (e.g. files in /var/log/) must not be set world-readable unless there is a functional reason to do so. By default, configuration files should be chmod 600 or 0640 and log files should be chmod 0600. This is due to a continuing number of security issues with world readable files that contain sensitive information (e.g. passwords and access tokens or logged usernames and commands for example).