added skippability and escapability tests, including SMIL but without audio (note: OPF duration metadata is set at 1s, until we include proper audio files)
use a different escapability name, as sidebar is also skippable
embedded media test (auncherOSX passes)
test for phrase-level navigation (audio previous/next granularity sentence/word/paragraph, etc.)
granularity fixes
added video embedded
playback active class test