[selectors] Also remove the nesting restriction from :matches().

Author: tabatkins

selectors/Overview.bs

@@ -1197,24 +1197,17 @@ Selector Lists</h3>
 The Matches-Any Pseudo-class: '':matches()''</h3>
 
 	The matches-any pseudo-class, <dfn id='matches-pseudo'>:matches()</dfn>,
-	is a functional pseudo-class taking a <a href="#grouping">selector list</a>
+	is a functional pseudo-class taking a <a>selector list</a>
 	as its argument. It represents an element that is represented by its argument.
 
-	The '':matches()'' pseudo-class may not be nested within itself
-	or within '':not()'':
-	'':matches(:matches(...))'' and '':not(:matches(...))'' are invalid.
-	Additionally, pseudo-elements cannot be represented by the matches-any pseudo-class;
+	Pseudo-elements cannot be represented by the matches-any pseudo-class;
 	they are not valid within '':matches()''.
 
-	Issue: This restriction probably isn't necessary.
-	If it is, it needs to be expanded,
-	since '':has()'' and '':nth-child()'' have the same functionality as '':matches()''.
-
 	Default namespace declarations do not affect any “implied” universal selectors
 	within a '':matches()'' pseudo-class.
 
 	<div class="example">
-		For example, following selector matches any element that is being
+		For example, the following selector matches any element that is being
 		hovered or focused, regardless of its namespace. In particular, it
 		is not limited to only matching elements in the default namespace
 		that are being hovered or focused.

selectors/Overview.html

@@ -1439,24 +1439,17 @@ <h3 class="heading settled heading" data-level=4.2 id=matches><span class=secno>
 The Matches-Any Pseudo-class: <a class=css data-link-type=maybe href=#matches-pseudo title=:matches()>:matches()</a></span><a class=self-link href=#matches></a></h3>
 
 <p>The matches-any pseudo-class, <dfn class=css-code data-dfn-type=selector data-export="" id=matches-pseudo>:matches()<a class=self-link href=#matches-pseudo></a></dfn>,
-	is a functional pseudo-class taking a <a href=#grouping>selector list</a>
+	is a functional pseudo-class taking a <a data-link-type=dfn href=#selector-list title="selector list">selector list</a>
 	as its argument. It represents an element that is represented by its argument.</p>
 
-<p>The <a class=css data-link-type=maybe href=#matches-pseudo title=:matches()>:matches()</a> pseudo-class may not be nested within itself
-	or within <a class=css data-link-type=maybe href=#negation-pseudo title=:not()>:not()</a>:
-	<span class=css data-link-type=maybe title=:matches(:matches(...))>:matches(:matches(...))</span> and <span class=css data-link-type=maybe title=:not(:matches(...))>:not(:matches(...))</span> are invalid.
-	Additionally, pseudo-elements cannot be represented by the matches-any pseudo-class;
+<p>Pseudo-elements cannot be represented by the matches-any pseudo-class;
 	they are not valid within <a class=css data-link-type=maybe href=#matches-pseudo title=:matches()>:matches()</a>.</p>
 
-<p class=issue id=issue-2adb46fb><a class=self-link href=#issue-2adb46fb></a>This restriction probably isn’t necessary.
-	If it is, it needs to be expanded,
-	since <a class=css data-link-type=maybe href=#has-pseudo title=:has()>:has()</a> and <a class=css data-link-type=maybe href=#nth-child-pseudo title=:nth-child()>:nth-child()</a> have the same functionality as <a class=css data-link-type=maybe href=#matches-pseudo title=:matches()>:matches()</a>.</p>
-
 <p>Default namespace declarations do not affect any “implied” universal selectors
 	within a <a class=css data-link-type=maybe href=#matches-pseudo title=:matches()>:matches()</a> pseudo-class.</p>
 
 	<div class=example>
-		For example, following selector matches any element that is being
+		For example, the following selector matches any element that is being
 		hovered or focused, regardless of its namespace. In particular, it
 		is not limited to only matching elements in the default namespace
 		that are being hovered or focused.
@@ -3934,9 +3927,7 @@ <h2 class="no-num heading settled" id=issues-index><span class=content>Issues In
 		or should we stick with defaulting to *not* allowing,
 		and requiring individual pseudo-classes to specify that they work on pseudo-elements?
 
-	<a href=#issue-73b391d2> ↵ </a></div><div class=issue>Explain this better.<a href=#issue-2422b936> ↵ </a></div><div class=issue>This restriction probably isn’t necessary.
-	If it is, it needs to be expanded,
-	since <a class=css data-link-type=maybe href=#has-pseudo title=:has()>:has()</a> and <a class=css data-link-type=maybe href=#nth-child-pseudo title=:nth-child()>:nth-child()</a> have the same functionality as <a class=css data-link-type=maybe href=#matches-pseudo title=:matches()>:matches()</a>.<a href=#issue-2adb46fb> ↵ </a></div><div class=issue>Add comma-separated syntax for
+	<a href=#issue-73b391d2> ↵ </a></div><div class=issue>Explain this better.<a href=#issue-2422b936> ↵ </a></div><div class=issue>Add comma-separated syntax for
 	<a href=http://lists.w3.org/Archives/Public/www-style/2011Mar/0215.html>multiple-value matching</a>?
 	e.g. [rel ~= next, prev, up, first, last]