add date_time library links

[SVN r14934]

libs/libraries.htm

@@ -98,6 +98,7 @@ out how to build object libraries, when needed.</p>
         Kevlin Henney.</li>
     <li><a href="crc/index.html">crc</a> - Cyclic Redundancy Code, from Daryle
       Walker.</li>
+    <li><a href="date_time/doc/index.html">date_time</a> - Date-Time library from Jeff Garland.</li>
     <li><a href="dynamic_bitset/dynamic_bitset.html">dynamic_bitset</a> - A runtime sized version of <tt>std::bitset</tt> from Jeremy Siek and Chuck Allison.</li>
     <li><a href="format/index.htm">format</a> - Type-safe 'printf-like' format 
     operations, from Samuel Krempp.</li>
@@ -415,6 +416,7 @@ out how to build object libraries, when needed.</p>
         Kevlin Henney.</li>
     <li><a href="crc/index.html">crc</a> - Cyclic Redundancy Code, from Daryle
       Walker.</li>
+    <li><a href="date_time/doc/index.html">date_time</a> - Date-Time library from Jeff Garland.</li>
     <li><a href="timer/index.htm">timer</a> - Event timer,
         progress timer, and progress display classes, from Beman
         Dawes.</li>