fix jshint problems and spelling
Change vtt track parser:
	- Lines no longer need to begin with a number. The information http://dev.w3.org/html5/webvtt/ indicates that each cue must have a timestamp and text; the chapter marker is optional
	- Add the now-optional chapter marker as a class on each cue when it is displayed, if one is specified
	- Add white-space: pre-wrap to the cue's css so the line breaks are honored