Added zoomable circle packing view (zoom-pack-hierarchy.xhtml)
Added per-document-topics.json (output generated by Topicalizer)
Updated zoom-pack-hierarchy.xhtml: category navigation enabled.
Update .gitignore
Updated zoom-pack-hierarchy.xhtml: categorization graph is now draggable. First approach to sticky sidebar.
Added styles.css
Updated zoom-pack-hierarchy.xhtml & styles.css: sidebar now lies in a fixed position