[MSE] Spec updates published

I have posted more changes to the Media Source
Extensions<https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html>
 spec.

Summary of changes:
Bug 19676 <https://www.w3.org/Bugs/Public/show_bug.cgi?id=19676>, Bug
20327<https://www.w3.org/Bugs/Public/show_bug.cgi?id=20327>- Provide
more detail for audio & video splicing.
Bug 20900 <https://www.w3.org/Bugs/Public/show_bug.cgi?id=20900> - Remove
complete access unit constraint.
Bug 20948 <https://www.w3.org/Bugs/Public/show_bug.cgi?id=20948>- Setting
timestampOffset in 'ended' triggers a transition to 'open'
Bug 20952 <https://www.w3.org/Bugs/Public/show_bug.cgi?id=20952> - Added
update event
Bug 20953 <https://www.w3.org/Bugs/Public/show_bug.cgi?id=20953> - Move end
of append event firing out of segment parser loop.
Bug 21034 <https://www.w3.org/Bugs/Public/show_bug.cgi?id=21034> - Add
steps to fire addtrack and removetrack events.

Diffs:
https://dvcs.w3.org/hg/html-media/rev/d5956e93b991

Aaron