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
Report the missing manifest reference for a page-map seperatly so it can have a different severity from other missing manifest errors
Merge pull request #429 from IDPF/p/apond/cr/opf_063

Report the missing manifest reference for a page-map separatly so it can...
Fix dc:type and dc:source rules for EPUB 3.0.1

The restriction to only one of these elements has been removed.
Added one test case for each element.
Simplify tests with a @Before setup  method
Add support for the 'source-of' OPF metadata

  * added it to the list of known properties
  * added Schematron checks for:
     * its allowed value
     * must have a `@refines`
     * the @refines target must be `dc:source`
  * added tests
Support for 'record' link elements (3.0.1)

  * link elements of type 'record' are now allowed
  * they must have a `media-type` attribute (schematron test)
  * they must not refine another property or element (schematron test)
Support collection-related OPF metadata

 * add 3.0.1 'belongs-to-collection' and 'collection-type' properties
 * 'belongs-to-collection' must either be publication-metadata or
   refine other 'belongs-to-collection' properties (schematron)
 * 'collection-type' must refine a 'belongs-to-collection' property
   (schematron)
Add support for vocabs
Improve prefix parsing

 * parsing is now done in `PrefixDeclarationParser`
 * parsing better supports edge cases and invalid characters
 * vocabs are computed in `VocabUtil#parsePrefixDeclaration`
 * added several new prefix-related error codes
 * thorough tests
Add known vocabs
Split property parsing into list & single-value