All extra-js in "dependencies"

jQuery and jQuery UI are now in the "dependencies/" directory
The legal manifest ...
Date info can be empty

To avoid "undefined" display for date of an image, the date info in
description field is now conditional
Correction in the manifest

I put the symbolic version "0.0.9" to force (me) to review the whole
thing and build a full demo presentation before "1.0.0"