hixie: Fix a few more details around orphaned nested browsing contexts. (whatwg r5704)

hixie: Fix a few more details around orphaned nested browsing contexts.
(whatwg r5704)

http://dev.w3.org/cvsweb/html5/spec/Overview.html?r1=1.4569&r2=1.4570&f=h
http://html5.org/tools/web-apps-tracker?from=5703&to=5704

===================================================================
RCS file: /sources/public/html5/spec/Overview.html,v
retrieving revision 1.4569
retrieving revision 1.4570
diff -u -d -r1.4569 -r1.4570
--- Overview.html	7 Dec 2010 00:21:57 -0000	1.4569
+++ Overview.html	7 Dec 2010 00:24:11 -0000	1.4570
@@ -41484,8 +41484,9 @@
    document</a> of <var title="">B</var>, or</li>
 
    <li>The browsing context <var title="">A</var> is a <a href="#nested-browsing-context">nested
-   browsing context</a> and its <a href="#top-level-browsing-context">top-level browsing
-   context</a> is <var title="">B</var>, or</li>
+   browsing context</a> with a <a href="#top-level-browsing-context">top-level browsing
+   context</a>, and its <a href="#top-level-browsing-context">top-level browsing context</a> is
+   <var title="">B</var>, or</li>
 
    <li>The browsing context <var title="">B</var> is an
    <a href="#auxiliary-browsing-context">auxiliary browsing context</a> and <var title="">A</var>
@@ -41582,8 +41583,8 @@
    context must be the current browsing context.</li>
 
    <li><p>If the given browsing context name is <code title="">_top</code>, then the chosen browsing context must be the
-   most <a href="#top-level-browsing-context">top-level browsing context</a> of the current
-   one.</li>
+   <a href="#top-level-browsing-context">top-level browsing context</a> of the current one, if
+   there is one, or else the current browsing context.</li>
 
    <li>