Cedar: various improvements to Proto

The PROTO structure is now used to identify the system as a whole, rather than a single protocol. It's stored and initialized in Server.

ProtoCompare(), ProtoAdd() and ProtoDetected() are renamed to make the difference between PROTO and PROTO_IMPL more clear.

ProtoGet() and ProtoNum() are removed because the related list can now be accessed directly by Server.

src/Cedar/Cedar.c

@@ -1606,9 +1606,6 @@ void InitCedar()
 
 	// Initialize protocol module
 	InitProtocol();
-
-	// Initialize third-party protocol interface
-	ProtoInit();
 }
 
 // Free Cedar communication module
@@ -1619,9 +1616,6 @@ void FreeCedar()
 		return;
 	}
 
-	// Free third-party protocol interface
-	ProtoFree();
-
 	// Free protocol module
 	FreeProtocol();
 }