archive module doesnt create directory entries

[Dennis Knochenwefel]

For example:

  archive:create(
     ("META-INF/container.xml"),
     ( content:metainf() ),
     <a:options>
       <a:skip-extra-attributes>true</a:skip-extra-attributes>
     </a:options>
  )

should create *2* entries automatically: one directory entry for META-INF and one file entry for META-INF/container.xml

Currently, the archive module only creates one file entry for META-INF/container.xml

As result the created zip archive is corrupt and cannot be read by some archive consumers (e.g. epub readers).

Additionally, as Luis pointed out, empty directories cannot be created automatically. Therefore, users should also be able to create directories manually.