Update media.html following audio and video html transformation fixes

- Remove "src" from audio and video tags as <source> is already used
- If autoplay is true, set autoplay="autoplay" in audio and video tags,
  if autoplay is false, remove the attribute
Add xsl/test/ to automated test suite

Use xsltproc to transform xsl/test/*.cnxml files with
xsl/cnxml-to-html5.xsl and compare with xsl/test/*.html files
Merge pull request #63 from Connexions/more-tests

Add xsl/test/ to python automated test suite
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)