Hi,
There is feature that implements this functionality on PBS' fork of django-filer.
The feature let's you upload an archive and then unpack it on the server side.
Unfortunately the PBS fork has diverged quite a lot from the filer you know, so you would have to cherrypick only the changesets that implement this particular feature and apply them on your own fork.
The changesets starting with LUN-367 and LUN-732 implement the 'archive' functionality I mentioned above.
Regards