add a Request::raw_post buffer

This buffer is used when a Function::NeedToCopyRawPost() method returned true.

while here:
- remove WINIX_POST_PARAMS and WINIX_RAW_POST_STRING plugin messages

winixd/core/pluginmsg.h

@@ -4,8 +4,8 @@
  * Author: Tomasz Sowa <t.sowa@ttmath.org>
  */
 
-/* 
- * Copyright (c) 2008-2022, Tomasz Sowa
+/*
+ * Copyright (c) 2008-2023, Tomasz Sowa
  * All rights reserved.
  * 
  * Redistribution and use in source and binary forms, with or without
@@ -282,20 +282,6 @@ namespace Winix
 // the session pointer in info is null
 #define WINIX_BASE_URL_REDIRECT				31030
 
-// raw POST parameters
-// in p1 there is a pointer to std::wstring meaning a parameter's name
-// in p2 there is a pointer to std::wstring value
-// this is sent only from PostParser
-// PostMultiParser (multipart/form-data html forms) doesn't send this messsage
-// there is no a session set (session pointer is null)
-// this message is sent for each name value pairs
-//
-#define WINIX_POST_PARAMS					31040
-
-// this is the raw string sent in POST method
-// in p1 there is a pointer to std::string object
-#define WINIX_RAW_POST_STRING				31050
-
 // this message is sent before calling MakePost() or MakeGet()
 // if you return false (which is default) you can prevent the access
 // to the resource