Added logic_script_client entity and a user message for calling a client-side function

sp/src/game/shared/usermessages.cpp

@@ -13,6 +13,10 @@
 
 void RegisterUserMessages( void );
 
+#ifdef MAPBASE
+void RegisterMapbaseUserMessages( void );
+#endif
+
 //-----------------------------------------------------------------------------
 // Purpose: Force registration on .dll load
 // FIXME:  Should this be a client/server system?
@@ -21,6 +25,11 @@ CUserMessages::CUserMessages()
 {
 	// Game specific registration function;
 	RegisterUserMessages();
+
+#ifdef MAPBASE
+	// Mapbase registration function;
+	RegisterMapbaseUserMessages();
+#endif
 }
 
 CUserMessages::~CUserMessages()