[selectors] Remove issue about match-sensitive specificity. Specify that the specificity of a :not() is the maximum of its branches.

Author: tabatkins

selectors/Overview.html

@@ -3918,14 +3918,13 @@ <h2 id=specificity><span class=secno>15. </span> Calculating a selector's
    <li>ignore the universal selector
   </ul>
 
-  <p>The specificity of a <a href="#negation">negation</a> or <a
-   href="#matches">matches</a> pseudo-class is the specificity of its most
-   specific argument. The pseudo-class itself does not count as pseudo-class.
-
-  <p class=issue>It would probably be better to have match-sensitive
-   specificity, if possible. See <a
-   href="http://lists.w3.org/Archives/Public/www-style/2010Sep/0534.html">dbaron's
-   message</a>.
+  <p>The specificity of a <a href="#matches">:matches()</a> pseudo-class is
+   the specificity of its most specific argument. The specificity of a <a
+   href="#negation">:negation()</a> pseudo-class is the maximum specificity
+   of any of its component selectors. In either case, the pseudo-class itself
+   does not contribute any additional specificity. For example,
+   <code>:matches(em, strong)</code> has a specificity of (0,0,1), like a tag
+   selector.
 
   <p> Specificities are compared by comparing the three components in order:
    the specificity with a larger <var>a</var> value is more specific; if the

selectors/Overview.src.html

@@ -2841,13 +2841,12 @@ <h2 id="specificity">
     <li>ignore the universal selector
   </ul>
 
-  <p>The specificity of a <a href="#negation">negation</a> or
-  <a href="#matches">matches</a> pseudo-class is the specificity
-  of its most specific argument. The pseudo-class itself does not
-  count as pseudo-class.
-
-  <p class="issue">It would probably be better to have match-sensitive
-    specificity, if possible. See <a href="http://lists.w3.org/Archives/Public/www-style/2010Sep/0534.html">dbaron's message</a>.
+  <p>The specificity of a <a href="#matches">:matches()</a> pseudo-class is 
+    the specificity of its most specific argument. 
+    The specificity of a <a href="#negation">:negation()</a> pseudo-class is
+    the maximum specificity of any of its component selectors.
+    In either case, the pseudo-class itself does not contribute any additional specificity.
+    For example, <code>:matches(em, strong)</code> has a specificity of (0,0,1), like a tag selector.
 
   <p>
     Specificities are compared by comparing the three components in order: