WIP: remove the old database abstraction layer

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

while here:
- remove: TextStream, SLog, TexTextStream

winixd/core/groups.cpp

@@ -59,7 +59,7 @@ void Groups::Clear()
 }
 
 
-void Groups::ReadGroups(Db * db)
+void Groups::ReadGroups()
 {
 	Clear();