- Add basic `biblioref` support. Its specific attributes are not handled yet.

- Allow the appendices to be followed by other sections.

- Add the ability to convert on the fly SVG figures to PDF through `inskscape`: apply patch #2821475 from David Necas.

- Improve the ability to format in bold or italic the elements embedded in `programlisting`s or `screen`s.

- Add the parameters:

  - `index.tocdepth`.

  - `index.numbered`.

  - `bibliography.tocdepth`.

  - `bibliography.numbered`.

  - `xref.hypermarkup`.

- A number of bug fixes.