Ideally we don't need this, but this with the directory
storage this is a user-input field which gets returned
by the storage's path() method which is used in various
external command calls.
By default a directory storage creates its path. In some
cases this can be undesired, mostly when storages have
nested paths (eg. a dir storage on a ZFS path or in an NFS
share, or inside custom mount points).
As a simple fix to this the 'mkdir' option (default ON)
can now be used to disable this behavior.
