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

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

doc/html/Environment.html

@@ -147,6 +147,8 @@ will display the current list of parameters and their effects.
 </address>
 
 Last modified:  14 October 1999
+<br>
+Describes HDF5 Release 1.2.2, June 2000
 
 </body>
 </html>