allow a request to be processed in a job

Now we allow a request to be passed into a job queue,
and after the job finishes the request is passed into
a controller again. In order to achieve this we have
a requests queue in System, when we put a request
to the job this Request structure is preserved in the
queue and for a new request a new Request is added to
the queue.

while here:
- remove App::Lock()/Unlock(), use scoped locking
- fix: Plugin now has a Call method which takes ModelConnector
  and a logger (used in multithreaded environment)
- BaseThread has a main_model_connector pointer
  to the main (from the main thread) model connector
- the FastCGI structure fcgi_request moved from App to Request
- some methods for handling requests moved from App to Request
- small refactoring in main.cpp
- add Http class (a http client)

winixd/core/session.h

@@ -5,7 +5,7 @@
  */
 
 /* 
- * Copyright (c) 2008-2021, Tomasz Sowa
+ * Copyright (c) 2008-2022, Tomasz Sowa
  * All rights reserved.
  * 
  * Redistribution and use in source and binary forms, with or without
@@ -66,7 +66,7 @@ public:
 	void ClearAfterRequest();
 
 
-	// 0 - means that there is a temporary session
+	// 0 - means that this is a temporary session
 	long id;
 	
 	// a session index
@@ -101,10 +101,17 @@ public:
 	bool remember_me;
 
 
-	// if true then this session will be removed by SessionManager
-	// without checking the time expiration
+	// if remove_me is true and if allow_to_delete is true then this session will be
+	// removed by SessionManager without checking the time expiration
 	bool remove_me;
 
+	// if the session can be removed then this value is true (default)
+	// if we continue a request from a controller to a job
+	// then we set this value to false in order for the SessionManager
+	// to not delete this
+	bool allow_to_delete;
+
+
 	PluginData plugin_data;
 
 
@@ -133,6 +140,8 @@ public:
 
 
 
+	bool is_temporary_session() const;
+
 };