use the data-type attribute instead of class
replace data-class with just class and fix code
remove xhtml namespace
clean up the HTML and some conversion back to cnx
add abstract data-type
change spans to *
hack to get notes with headings to be valid cnxml
add the book title and abstract
Merge pull request #59 from Connexions/phil-cleanup

Format cleanup
Transform youtube videos and videos not supported by html5 video tag

- embed youtube videos using iframes
- transform videos that are not "video/mp4", "video/ogg" and
  "video/webm" to embed tags (like legacy)
Merge pull request #62 from Connexions/fix-youtube-embeded-videos

Transform youtube videos and videos not supported by html5 video tag
Append a glossary section to the end of transformed html.
Add a definition prefix to inline defined terms.
Use data-type rather than class.