[css3-ui] 6.1 should say 'pseudo-element'

If the 'content' property in terms of CSS 3 UI really is the same as in 
CSS 2.1 only extended with a new value it should read "pseudo-element" 
not "(pseudo-)element"[1].


[1]<http://www.w3.org/TR/2004/CR-css3-ui-20040511/#content0>


-- 
  Anne van Kesteren
  <http://annevankesteren.nl/>