update to current rack middleware stack

guides/source/rails_on_rack.textile

@@ -91,22 +91,25 @@ For a freshly generated Rails application, this might produce something like:
 <ruby>
 use ActionDispatch::Static
 use Rack::Lock
-use ActiveSupport::Cache::Strategy::LocalCache
+use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x000000029a0838>
 use Rack::Runtime
+use Rack::MethodOverride
+use ActionDispatch::RequestId
 use Rails::Rack::Logger
 use ActionDispatch::ShowExceptions
 use ActionDispatch::DebugExceptions
 use ActionDispatch::RemoteIp
-use Rack::Sendfile
+use ActionDispatch::Reloader
 use ActionDispatch::Callbacks
 use ActiveRecord::ConnectionAdapters::ConnectionManagement
 use ActiveRecord::QueryCache
 use ActionDispatch::Cookies
 use ActionDispatch::Session::CookieStore
 use ActionDispatch::Flash
 use ActionDispatch::ParamsParser
-use Rack::MethodOverride
 use ActionDispatch::Head
+use Rack::ConditionalGet
+use Rack::ETag
 use ActionDispatch::BestStandardsSupport
 run Blog::Application.routes
 </ruby>