Issue 131 text baseline

In the chairs decision on Issue 131 the text baseline the chairs stated
that there was not adequate information to define the text baseline and
therefore it was not adopted:
http://lists.w3.org/Archives/Public/public-html/2011Apr/0271.html

In discussions with Maciej to provide clarification I agreed to provide
more information on on text baseline for Issue 131.

http://lists.w3.org/Archives/Public/public-html/2011Apr/0426.html

I modified the original change proposal to provide more detail on the
computation of text baseline in the text metrics. That information is
included in this change proposal:
http://www.w3.org/html/wg/wiki/ChangeProposals/CaretSelection

Please review.

Thanks,
Rich

Rich Schwerdtfeger
CTO Accessibility Software Group