(svn r15488) -Change [API CHANGE]: Add support for distant-join stations.

src/ai/api/ai_station.hpp

@@ -49,6 +49,12 @@ public:
 		STATION_ANY        = 0x1F, //!< All station types
 	};
 
+	enum SpecialStationIDs {
+		STATION_NEW = 0xFFFD,           //!< Build a new station
+		STATION_JOIN_ADJACENT = 0xFFFE, //!< Join an neighbouring station if one exists
+		STATION_INVALID = 0xFFFF,       //!< Invalid station id.
+	};
+
 	/**
 	 * Checks whether the given station is valid and owned by you.
 	 * @param station_id The station to check.