[ttml2] Pull Request: Add alternateText named metadata item (#107).

skynavga has just submitted a new pull request for 
https://github.com/w3c/ttml2:

== Add alternateText named metadata item (#107). ==
See issue #107.

See https://github.com/w3c/ttml2/pull/183

Received on Thursday, 15 September 2016 19:39:58 UTC