Multi-layers support with Nuxeo Enhanced Viewer

We want to add to to Nuxeo enhanced viewer the support for layers based documents: like in adobe acrobat, user can select / unselect available layers, which updates the rendering of the document. We want this support for PDF first, followed by PSD and in the future we should want this for Autocad document and other kinds of layers based documents. 

Also, we need to cover:

• first the dynamical rendition aspects and user controls
• second,, how to bind an annotation specifically when a given layer is displayed.