Archives supported by the XAD system are just a collection of files that are stored at indices
ranging from 0 to the number of entries in the archive minus 1. It is not necessary to store
directories as individual entries. Instead, they can also be stored as part of a filename, e.g.
if a file is stored as
a/b/c/test.txt in the archive, then the directories a, b, and c
are implicitly declared as existing even though they don't have their individual entries
in the archive but just exist as part of a file. You have to be prepared to deal with that
if you manually parse archives using the functions provided by this plugin.