Remove some IMHO dangerous functions

Instead, these functions are now inlined into their only caller. This should
make the user and network destruction a little saner. At least I hope so...

Signed-off-by: Uli Schlachter <psychon@znc.in>

znc.cpp

@@ -180,12 +180,7 @@ bool CZNC::HandleUserDeletion()
 			}
 		}
 
-		pUser->DelNetworks();
-		pUser->DelClients();
-		pUser->DelModules();
 		CWebSock::FinishUserSessions(*pUser);
-		AddBytesRead(pUser->BytesRead());
-		AddBytesWritten(pUser->BytesWritten());
 		delete pUser;
 	}