[MEDIA] Updated MAUR

I have made the various edits we agreed at the last meeting of the Media
subteam.  They are available in the live Editor's Draft at
http://w3c.github.io/pfwg/media-accessibility-reqs/

Note that this includes a snapshot of the checklist as we agreed.  I may do
some work connecting the checklist to the embedded content if I can
automate it.

-- 
Shane McCarron
Managing Director, Applied Testing and Technology, Inc.