[selectors] Make :lang() argument an ident or string, per WG resolution.

Author: tabatkins

selectors/Overview.bs

@@ -202,7 +202,7 @@ Selectors Overview</h2>
 				<td>[[#the-dir-pseudo]]
 				<td>4
 			<tr>
-				<td><code>E:lang(zh, *-hant)</code>
+				<td><code>E:lang(zh, "*-hant")</code>
 				<td>an element of type E tagged as being either in Chinese
 					(any dialect or writing system)
 					or othewise written with traditional Chinese characters
@@ -1905,10 +1905,9 @@ The Language Pseudo-class: '':lang()''</h3>
 	is in one of the languages listed in its argument. It accepts
 	a comma-separated list of one or more <a>language ranges</a> as its
 	argument. Each <dfn>language range</dfn> in '':lang()''
-	must be a valid CSS <a href="http://www.w3.org/TR/CSS21/syndata.html#value-def-identifier">identifier</a>
-	[[!CSS21]]
-	or consist of an asterisk (* U+002A) immediately followed by an identifier
-	beginning with an ASCII hyphen (U+002D) for the selector to be valid.
+	must be a valid CSS <<ident>> or <<string>>.
+	(Language ranges containing asterisks, for example,
+		must be quoted as strings.)
 
 	The <dfn>language</dfn> of an element is defined by the document language.
 	For example, in HTML [[HTML401]], the <a>language</a> is determined by a