WIP: remove the old database abstraction layer

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

while here:
- remove: TextStream, SLog, TexTextStream

winixd/core/session.cpp

@@ -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
@@ -105,7 +105,6 @@ void Session::Clear(bool clear_plugin_data)
 	start_date.Clear();
 	last_date.Clear();
 
-	log_buffer.Clear();
 	last_css.clear();
 	ip_ban = 0;