Add support for RDFa attributes.
Add support for defaultAction, phase and propagate on epub:trigger
Add support for Microdata attributes
Add support for custom ns attributes in xhtml content docs
Add support for aria-describedat in XHTML, add support for epub:type on
SVG.
Add new set of recognized epub:type values (301)
Additional microdata tweaks
Disable a test verbosity flag
Merge pull request #428 from IDPF/301-update/contentdocs

Updates to Content Doc checks for EPUB 3.0.1