CLIDSvc: Remove some unused forwarding headers.

The forwarding headers under CLIDSvc/tools are no longer referenced
from anywhere.  Remove them.

Control/CLIDSvc/CLIDSvc/tools/CLIDRegistry.h

-/*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
-*/
-
-#ifndef TOOLS_CLIDREGISTRY_H
-# define TOOLS_CLIDREGISTRY_H
-
-// forwarding to 'real' CLIDRegistry
-#include "SGTools/CLIDRegistry.h"
-
-#endif // TOOLS_CLIDREGISTRY_H

Control/CLIDSvc/CLIDSvc/tools/ClassID_traits.h

-/*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
-*/
-
-#ifndef TOOLS_CLASSID_TRAITS_H
-#define TOOLS_CLASSID_TRAITS_H
-
-// forwarding to 'real' ClassID_traits
-#include "SGTools/ClassID_traits.h"
-
-#endif
-
-
-
-
-