daemon: Enable to handle user defined control codes

128 to 255 for windows service's control codes are user-defined:

  https://docs.microsoft.com/en-us/windows/win32/api/winsvc/nf-winsvc-controlservice

but win32-service doesn't handle these codes.

This commit adds a handler for them.

doc/daemon.txt

@@ -92,6 +92,9 @@ Daemon#service_paramchange
   Called if the service receives a SERVICE_CONTROL_PARAMCHANGE signal.
   This notifies a service that its startup parameters have changed.
 
+Daemon#service_user_defined_control(code)
+  Called if the service receives a user-defined control code (128 to 255).
+
 = Constants
 
 === Service state constants

lib/win32/daemon.rb

@@ -304,6 +304,14 @@ def mainloop
               when SERVICE_CONTROL_NETBINDDISABLE
                 service_netbinddisable() if respond_to?('service_netbinddisable')
             end
+
+            # handle user defined control codes
+            if @@waiting_control_code >= 128 && @@waiting_control_code <= 255
+              if respond_to?('service_user_defined_control')
+                service_user_defined_control(@@waiting_control_code)
+              end
+            end
+
             @@waiting_control_code = IDLE_CONTROL_CODE
           end