[css3-text] fullwidth punctuation kerning

Section 7.3 of the CSS3 Text spec details a property that effectively
controls kerning on a small subset of CJK punctuation characters:

  http://dev.w3.org/csswg/css3-text/#punctuation-trim

I don't quite see the necessity of of an author level property to
control this unless it's something that is really controlled at an
author level stylistically.  In fact, supporting this in a browser
that uses an OpenType layout engine would effectively require
*undoing* layout based kerning information contained in fonts,
especially since the default is 'none'.

I think it would be better omit this property and let the text layout
engine handle this in conjuction with well-designed fonts.

John Daggett