Action 217: Create an updated Caret ring focus (Rich, Ted, Frank)

Sam, Paul,

A while back I was asked by Sam to pull in the use cases from WhatWG Wiki
that applied to rich text editing and caret/selection tracking and place
them in the revised ARIA change proposal. I have done that. Most of the use
cases in the WhatWG WIKi pertain to the need for hit testing and providing
location information to assistive technologies.

These changes are in the Rationale section of the change proposal and they
encompass LibreOffice and rhw Lucidart drawing tool.

http://www.w3.org/html/wg/wiki/ChangeProposals/CaretSelectionRevised

Rich