WIP: remove the old database abstraction layer

remove such classes:
- DbBase
- DbConn
- DbTextStream
- Db

while here:
- remove: TextStream, SLog, TexTextStream

winixd/core/session.h

@@ -5,7 +5,7 @@
  */
 
 /* 
- * Copyright (c) 2008-2022, Tomasz Sowa
+ * Copyright (c) 2008-2024, Tomasz Sowa
  * All rights reserved.
  * 
  * Redistribution and use in source and binary forms, with or without
@@ -43,7 +43,6 @@
 #include "models/user.h"
 #include "plugindata.h"
 #include "rebus.h"
-#include "textstream.h"
 #include "date/date.h"
 #include "ipban.h"
 
@@ -115,9 +114,6 @@ public:
 	PluginData plugin_data;
 
 
-	// buffer for the session log
-	TextStream<std::wstring> log_buffer;
-
 	// !! IMPROVE ME it is still needed?
 	// css cannot be taken directly from the mountpoint?
 	// table with css files