(svn r5946) -Add: merged the TGP branch to mainline. TGP adds:

- New optional landscape generator (TerraGenesis Perlin)
  - Load heightmaps (either BMP or PNG)
  - Progress dialog while generating worlds (no longer a 'hanging' screen)
  - New dialogs for NewGame, Create Scenario and Play Heightmap
    - Easier to configure your landscape
    - More things to configure (tree-placer, ..)
  - Speedup of world generation
  - New console command 'restart': restart the map EXACTLY as it was when you
      first started it (needs a game made after or with this commit)
  - New console command 'getseed': get the seed of your map and share it with
      others (of course only works with generated maps)
  - Many new, world generation related, things
  - Many internal cleanups and rewrites
  Many tnx to those people who helped making this:
     Belugas, DaleStan, glx, KUDr, RichK67, Rubidium, and TrueLight (alfabetic)
  Many tnx to those who helped testing:
     Arnau, Bjarni, and tokai (alfabetic)
  And to all other people who helped testing and sending comments / bugs
  Stats: 673 lines changed, 3534 new lines, 79 new strings

genworld.h

@@ -0,0 +1,91 @@
+/* $Id$ */
+
+#ifndef GENWORLD_H
+#define GENWORLD_H
+
+/* If OTTDThread isn't defined, define it to a void, but make sure to undefine
+ *  it after this include. This makes including genworld.h easier, as you
+ *  don't need to include thread.h before it, while it stays possible to
+ *  include it after it, and still work.
+ */
+#ifndef OTTDThread
+#define TEMPORARY_OTTDTHREAD_DEFINITION
+#define OTTDThread void
+#endif
+
+/*
+ * Order of these enums has to be the same as in lang/english.txt
+ * Otherwise you will get inconsistent behaviour.
+ */
+enum {
+	LG_ORIGINAL     = 0,  //! The original landscape generator
+	LG_TERRAGENESIS = 1,  //! TerraGenesis Perlin landscape generator
+
+	GENERATE_NEW_SEED = (uint)-1, //! Create a new random seed
+};
+
+typedef void gw_done_proc(void);
+
+typedef struct gw_info {
+	bool active;           //! Is generating world active
+	bool abort;            //! Whether to abort the thread ASAP
+	bool wait_for_draw;    //! Are we waiting on a draw event
+	bool quit_thread;      //! Do we want to quit the active thread
+	bool threaded;         //! Whether we run _GenerateWorld threaded
+	int mode;              //! What mode are we making a world in
+	byte lp;               //! The local_player before generating
+	uint size_x;           //! X-size of the map
+	uint size_y;           //! Y-size of the map
+	gw_done_proc *proc;    //! Proc that is called when done (can be NULL)
+	OTTDThread *thread;    //! The thread we are in (can be NULL)
+} gw_info;
+
+#ifdef TEMPORARY_OTTDTHREAD_DEFINITION
+#undef OTTDThread
+#undef TEMPORARY_OTTDTHREAD_DEFINITION
+#endif
+
+typedef enum gwp_classes {
+	GWP_MAP_INIT,    /* Initialize/allocate the map, start economy */
+	GWP_LANDSCAPE,   /* Create the landscape */
+	GWP_ROUGH_ROCKY, /* Make rough and rocky areas */
+	GWP_TOWN,        /* Generate towns */
+	GWP_INDUSTRY,    /* Generate industries */
+	GWP_UNMOVABLE,   /* Generate unmovables (radio tower, light houses) */
+	GWP_TREE,        /* Generate trees */
+	GWP_GAME_INIT,   /* Initialize the game */
+	GWP_RUNTILELOOP, /* Runs the tile loop 1280 times to make snow etc */
+	GWP_GAME_START,  /* Really prepare to start the game */
+	GWP_CLASS_COUNT
+} gwp_class;
+
+/**
+ * Check if we are currently in the process of generating a world.
+ */
+static inline bool IsGeneratingWorld(void)
+{
+	extern gw_info _gw;
+
+	return _gw.active;
+}
+
+/* genworld.c */
+void SetGeneratingWorldPaintStatus(bool status);
+bool IsGeneratingWorldReadyForPaint(void);
+bool IsGenerateWorldThreaded(void);
+void GenerateWorldSetCallback(gw_done_proc *proc);
+void WaitTillGeneratedWorld(void);
+void GenerateWorld(int mode, uint size_x, uint size_y);
+void AbortGeneratingWorld(void);
+bool IsGeneratingWorldAborted(void);
+void HandleGeneratingWorldAbortion(void);
+
+/* genworld_gui.c */
+void SetGeneratingWorldProgress(gwp_class class, uint total);
+void IncreaseGeneratingWorldProgress(gwp_class class);
+void PrepareGenerateWorldProgress(void);
+void ShowGenerateWorldProgress(void);
+void StartNewGameWithoutGUI(uint seed);
+void ShowCreateScenario(void);
+
+#endif /* GENWORLD_H */