sessions are not saved on a redirect

[bbleything]

Consider the following:

def redirect_home_with_message( txn, message )
 	txn.session[ :message ] = message
 	return txn.redirect( txn.applet_uri )
end

The session is not saved in this case. Line 281ish of source:trunk/lib/arrow/dispatcher.rb opens a conditional that results in the session only being saved when the transaction status is Apache::OK, which is apparently not true for a redirect.