Only check / and /config for config.xml. Otherwise you might step on a nanobsd installation.
Adding external configuration loader which will look on all found disks except bootup disk for config.xml. If tconfig.xml is found on an external disk then it tests the roobobj to ensure its a valid file then calls test_config() to ensure it is a valid xml file. Once the file is validated a backup_config() is called to backup the current configuration and finally the file is installed using restore_backup()