Bit Cleanup + valid HTML menu

- this fixes some issues in #170.
- More improvements added.
- Deprecated code removed (in js/app.js, *.css )
- Valid HTML output.
- CSS valid code, nicely formatted, regrouped and reorganized.
- `<small>` was eliminated in favor of `<span class="node_name">`, since presentation shouldn't be represented in the html structure. small should be left for copyright notices or side comments.