The concept of an 'unsealed' RealmFS no longer exists so support for this has been
removed. The result is much less complex and easier to understand and maintain.
Now if a variable is not set in a realm config file (or the file does
not exist), the 'global' config file will also be searched in the
parent directory (ie: /storage/realms/config). If the variable is
still not found, the value from the default instance is returned.
