FAT-16 exposes volume label as a directory entry

org.jnode.fs.fat.FatDirectory.iterator() returns an iterator which contains the magic entry for the volume label.

The entry is not a directory and not a file, so the caller can't do anything useful with it.

I think that the entry should be skipped when the caller asks for the list of entries in the directory; the volume label should be exposed through some other mechanism (e.g. filesystem metadata) which can then be standardised for other filesystems.