ACTION-2086: Add text role back to spec

After re-reading the discussion on this topic, there wasn't enough in the meeting minutes to warrant its removal.
http://www.w3.org/2016/03/31-aria-minutes.html#item04

The feature was already approved for 1.1 (in the January 2014 F2F meeting), it was one of the first features added to the spec (along with appropriate warning text), and already had two shipping implementations at the time of its removal.

The text role should be uncommented and moved back into the spec.

Given all that, the only thing warranting its removal would be:

1) An agreement that the feature is not, in fact, useful. (effectively like deprecation)
2) A formal statement from one of the browsers vendors that the feature is not implementable on a particular platform.

A proposal for a rewritten version of the text is introduced in: https://lists.w3.org/Archives/Public/public-aria/2016Jun/0274.html

That message includes a summary of what led to the proposed rewrite and explicitly requests review from group members.

This was done via github branch and is being tracked it github. Closing as a duplicate.