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/webrick_server.rb

@@ -43,8 +43,6 @@ end
 # can change this behavior by setting ActionController::Base.allow_concurrency
 # to true.
 class DispatchServlet < WEBrick::HTTPServlet::AbstractServlet
-  REQUEST_MUTEX = Mutex.new
-
   # Start the WEBrick server with the given options, mounting the
   # DispatchServlet at <tt>/</tt>.
   def self.dispatch(options = {})
@@ -74,15 +72,8 @@ class DispatchServlet < WEBrick::HTTPServlet::AbstractServlet
 
   def service(req, res) #:nodoc:
     unless handle_file(req, res)
-      begin
-        REQUEST_MUTEX.lock unless ActionController::Base.allow_concurrency
-        unless handle_dispatch(req, res)
-          raise WEBrick::HTTPStatus::NotFound, "`#{req.path}' not found."
-        end
-      ensure
-        unless ActionController::Base.allow_concurrency
-          REQUEST_MUTEX.unlock if REQUEST_MUTEX.locked?
-        end
+      unless handle_dispatch(req, res)
+        raise WEBrick::HTTPStatus::NotFound, "`#{req.path}' not found."
       end
     end
   end