Upgrade to Rails 2.2.0

As a side benefit, fix an (non-user-visible) bug in display_s5().
Also fixed a bug where removing orphaned pages did not expire cached summary pages.

vendor/rails/railties/lib/test_help.rb

@@ -8,7 +8,6 @@ require 'test/unit'
 require 'active_support/test_case'
 require 'active_record/fixtures'
 require 'action_controller/test_case'
-require 'action_controller/test_process'
 require 'action_controller/integration'
 require 'action_mailer/test_case' if defined?(ActionMailer)
 
@@ -25,4 +24,4 @@ begin
   Debugger.settings[:autoeval] = true if Debugger.respond_to?(:settings)
 rescue LoadError
   # ruby-debug wasn't available so neither can the debugging be
-end
+end