Changed last two remaining uses of "./" to "index.html" when referring to the

index file for the top-level directory.  This makes it easier to use an
unpacked version of the documentation via file: URLs.
This closes SF bug #541257.

Doc/html/about.html

@@ -13,7 +13,7 @@
           <tr>
             <td><img width="32" height="32" align="bottom" border="0" alt=""
                 src="icons/blank.gif"></td>
-            <td><a href="./"
+            <td><a href="index.html"
                 title="Python Documentation Index"><img width="32" height="32"
                   align="bottom" border="0" alt="up"
                   src="icons/up.gif"></a></td>
@@ -30,7 +30,7 @@
       </table>
       <b class="navlabel">Up:</b>
       <span class="sectref">
-        <a href="./" title="Python Documentation Index">
+        <a href="index.html" title="Python Documentation Index">
           Python Documentation Index</A></span>
       <br>
     </div>