I added some notes about the upgrade to Apache Cocoon-2.1 version.

Please review r694614 which added upgrading notes to
upgrading_09.html#cocoon and an entry in the Changes list.
http://svn.apache.org/viewvc?view=rev&revision=694614
or type "694614" in Forrestbar and search "SVN Revision".

I trust that it casts this move in its positive light.
If not then please patch.

-David