[csswg] Update [HTML5] ref.

Author: tabatkins

biblio.ref

@@ -2271,8 +2271,8 @@
 %A Ian Hickson
 %S W3C Candidate Recommendation
 %O (Work in progress.)
-%D 6 August 2013
-%U http://www.w3.org/TR/2013/CR-html5-20130806/
+%D 17 June 2014
+%U http://www.w3.org/TR/2014/WD-html5-20140617/
 
 %L HTML5-AUTHOR
 %T HTML5: Edition for Web Authors