[svn-r2381] Added line to each HTML doc file noting release number.

In many cases, also updated "Last modified:" date.

doc/html/Datasets.html

@@ -929,8 +929,10 @@ H5Pset_external (plist, "scan3.data", 0, 16);
 
 <!-- Created: Tue Dec  2 09:17:09 EST 1997 -->
 <!-- hhmts start -->
-Last modified:  14 October 1999
+Last modified:  7 April 2000
 <!-- hhmts end -->
+<br>
+Describes HDF5 Release 1.2.2, June 2000
 
   </body>
 </html>