Bulk updates.

- Changed the architecture of the integration code so that TextTrackCue
now handles all the conversion of the node data to DOM data as well
as handling the attaching of the doc frag to the caption overlay.
- Removed some uneeded includes for the c webvtt parser stuff.
Merge pull request #9 from RickEyre/integration-arch-change

Bulk updates.
Added processing instruction for timestamp.

- Added convert to processing instruction in DOM for timestamp.
- Simplified nsINode code.
- Added support for css classes.
Update webvtt to 34cd4dba44e.

Aka merge filestruct-fix branch.
Merge branch 'integration' of github.com:RickEyre/mozilla-central into integration5

Conflicts:
	content/html/content/src/HTMLTrackElement.cpp
	content/html/content/src/WebVTTLoadListener.cpp
	media/webvtt/parser.c
Merge branch 'integration' of github.com:RickEyre/mozilla-central into integration5

Conflicts:
	content/html/content/src/HTMLTrackElement.cpp
	content/html/content/src/HTMLTrackElement.h
	content/html/content/src/WebVTTLoadListener.cpp
	content/html/content/src/WebVTTLoadListener.h
	media/webvtt/parser.c
Moved adding the caption overlay child div to TextTrackCue.