Codechange: Split CT_INVALID into CT_INVALID and INVALID_CARGO.

INVALID_CARGO is a CargoID and should be used for most purposes in game.
CT_INVALID is a CargoType used for defining default properties.

src/linkgraph/linkgraph.h

@@ -189,7 +189,7 @@ public:
 	}
 
 	/** Bare constructor, only for save/load. */
-	LinkGraph() : cargo(CT_INVALID), last_compression(0) {}
+	LinkGraph() : cargo(INVALID_CARGO), last_compression(0) {}
 	/**
 	 * Real constructor.
 	 * @param cargo Cargo the link graph is about.

src/linkgraph/linkgraph_gui.h

@@ -21,7 +21,7 @@
  * Only the cargo type of the most saturated linkgraph is taken into account.
  */
 struct LinkProperties {
-	LinkProperties() : cargo(CT_INVALID), capacity(0), usage(0), planned(0), shared(false) {}
+	LinkProperties() : cargo(INVALID_CARGO), capacity(0), usage(0), planned(0), shared(false) {}
 
 	/** Return the usage of the link to display. */
 	uint Usage() const { return std::max(this->usage, this->planned); }

src/linkgraph/refresh.cpp

@@ -67,7 +67,7 @@ bool LinkRefresher::Hop::operator<(const Hop &other) const
  * @param is_full_loading If the vehicle is full loading.
  */
 LinkRefresher::LinkRefresher(Vehicle *vehicle, HopSet *seen_hops, bool allow_merge, bool is_full_loading) :
-	vehicle(vehicle), seen_hops(seen_hops), cargo(CT_INVALID), allow_merge(allow_merge),
+	vehicle(vehicle), seen_hops(seen_hops), cargo(INVALID_CARGO), allow_merge(allow_merge),
 	is_full_loading(is_full_loading)
 {
 	memset(this->capacities, 0, sizeof(this->capacities));

src/linkgraph/refresh.h

@@ -56,7 +56,7 @@ protected:
 	struct Hop {
 		OrderID from;  ///< Last order where vehicle could interact with cargo or absolute first order.
 		OrderID to;    ///< Next order to be processed.
-		CargoID cargo; ///< Cargo the consist is probably carrying or CT_INVALID if unknown.
+		CargoID cargo; ///< Cargo the consist is probably carrying or INVALID_CARGO if unknown.
 
 		/**
 		 * Default constructor should not be called but has to be visible for