Add a plugin to handle session persistence. This is based on the

plugin at http://github.com/augustl/session-persistence but modified
to work with rails 2 rather than rails 3.

vendor/plugins/session-persistence/init.rb

@@ -0,0 +1,3 @@
+require  "session_persistence"
+ActionController::Base.class_eval { include SessionPersistence }
+ActionController::Base.after_filter :_persist_session