EPUB 2.5.4/3.2 Support

EPUB transform appears to work with Open Toolkit 2.5.4 and 3.2, although it has not been extensively tested.

Fixes a bug in the handling of the CSS directory that caused bad URLs for references to CSS files in a directory specified with the args.csspath Open Toolkit option.

Now uses the base HTML5 transform rather than the XHTML transform as the base for HTML generation. If you have XHTML extensions that extend the XHTML transform and you want those to be used for EPUB you will need to update them to extend the HTML5 transform instead. For most extensions this should be as easy as adding the HTML5 extension point along side the XHTML extension point in your plugin's plugin.xml file.

Also includes the latest Word2DITA code, which fixes a couple of small bugs.