(svn r6055) -Codechange: added GetXXXArraySize, which returns HighestID + 1 (or, will do that).

It isn't the best name, but we couldn't find any better.
  This unifies the pool-system even more.

vehicle.h

@@ -359,6 +359,16 @@ static inline uint16 GetVehiclePoolSize(void)
 	return _vehicle_pool.total_items;
 }
 
+static inline VehicleID GetVehicleArraySize(void)
+{
+	/* TODO - This isn't the real content of the function, but
+	 *  with the new pool-system this will be replaced with one that
+	 *  _really_ returns the highest index + 1. Now it just returns
+	 *  the next safe value we are sure about everything is below.
+	 */
+	return GetVehiclePoolSize();
+}
+
 /**
  * Check if a Vehicle really exists.
  */