rational number library overhaul

[SVN r8953]

index.htm

@@ -74,6 +74,8 @@ with any concerns you don't want to just post to the mailing list.</p>
       <li>Added the <a href="libs/graph/doc/filtered_graph.html">
         <tt>filtered_graph</tt></a> class adaptor.</li>
    </ol></li>
+  <li><a href="libs/rational/index.html">Rational Number Library</a>: documentation updates,
+efficiency improvements, co-operates with user-defined types, regression tests
 </ul>
 <p>January 10, 2001 - Version 1.20.1</p>
 <ul>