[css-scoping] Clarify that :host-context() is allowed to match the host element.

Author: tabatkins

css-scoping/Overview.bs

@@ -236,7 +236,7 @@ Host Elements in a Shadow Tree</h4>
 	not the other <a>shadow trees</a>.
 
 	The <a>host element</a> is not selectable by <strong>any means</strong>
-	except for the '':host'' pseudo-class.
+	except for the '':host'' and '':host-context()'' pseudo-classes.
 	That is, in this context the <a>shadow host</a>
 	has no tagname, ID, classes, or attributes,
 	and the only additional information is has is that the '':host'' pseudo-class matches it.

css-scoping/Overview.html

@@ -54,7 +54,7 @@
 </p>
   <h1 class="p-name no-ref" id=title>CSS Scoping Module Level 1</h1>
   <h2 class="no-num no-toc no-ref heading settled heading" id=subtitle><span class=content>Editor’s Draft,
-    <span class=dt-updated><span class=value-title title=20140321>21 March 2014</span></span></span></h2>
+    <span class=dt-updated><span class=value-title title=20140322>22 March 2014</span></span></span></h2>
   <div data-fill-with=spec-metadata><dl><dt>This version:<dd><a class=u-url href=http://dev.w3.org/csswg/shadow-styling>http://dev.w3.org/csswg/shadow-styling</a><dt>Editor’s Draft:<dd><a href=http://dev.w3.org/csswg/shadow-styling>http://dev.w3.org/csswg/shadow-styling</a>
     <dt>Feedback:</dt>
         <dd><a href="mailto:www-style@w3.org?subject=%5Bcss-scoping%5D%20feedback">www-style@w3.org</a>
@@ -366,7 +366,7 @@ <h4 class="heading settled heading" data-level=3.1.1 id=host-element><span class
 	not the other <a data-link-type=dfn href=#shadow-tree title="shadow trees">shadow trees</a>.
 
 <p>	The <a data-link-type=dfn href=#host-element0 title="host element">host element</a> is not selectable by <strong>any means</strong>
-	except for the <a class=css data-link-type=maybe href=#selectordef-host0 title=:host>:host</a> pseudo-class.
+	except for the <a class=css data-link-type=maybe href=#selectordef-host0 title=:host>:host</a> and <a class=css data-link-type=maybe href=#selectordef-host-context title=:host-context()>:host-context()</a> pseudo-classes.
 	That is, in this context the <a data-link-type=dfn href=#shadow-host title="shadow host">shadow host</a>
 	has no tagname, ID, classes, or attributes,
 	and the only additional information is has is that the <a class=css data-link-type=maybe href=#selectordef-host0 title=:host>:host</a> pseudo-class matches it.