Changes in 2.31.3
=================
* Use text titles for link tooltips when present.
* Better support for mixed-directionality documents
* Style tweaks

Changes in 2.31.2
=================
* Added support for DocBook 5 (Brian M. Carlson)
* New common HTML output stylesheets (Shaun McCance)
* Removed numbering and labeling for DocBook (Shaun McCance)
* Better behavior for links to invalid targets (Shaun McCance)
