ICE-9499 restricted required/optional styling to only Overview and Required Styling demos; added 'None (Use theme)' checkbox in Required Styling demos; added background and text colours to error classes

git-svn-id: http://anonsvn.icesoft.org/repo/icefaces3/trunk/icefaces@37420 1de00972-ac04-4911-a46b-06793c8d78d9
ICE-9499 expanded explanation in Required Styling demos

git-svn-id: http://anonsvn.icesoft.org/repo/icefaces3/trunk/icefaces@37421 1de00972-ac04-4911-a46b-06793c8d78d9
ICE-8261 : IceClientBehaviorHolder specify their AjaxBehaviorEvent subclass

git-svn-id: http://anonsvn.icesoft.org/repo/icefaces3/trunk/icefaces@37422 1de00972-ac04-4911-a46b-06793c8d78d9