(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

gfx.c

@@ -12,6 +12,7 @@
 #include "table/sprites.h"
 #include "hal.h"
 #include "variables.h"
+#include "genworld.h"
 
 #ifdef _DEBUG
 bool _dbg_screen_rect;
@@ -1753,6 +1754,8 @@ void DrawDirtyBlocks(void)
 	int x;
 	int y;
 
+	if (IsGeneratingWorld() && !IsGeneratingWorldReadyForPaint()) return;
+
 	y = 0;
 	do {
 		x = 0;
@@ -1819,6 +1822,12 @@ void DrawDirtyBlocks(void)
 	_invalid_rect.top = h;
 	_invalid_rect.right = 0;
 	_invalid_rect.bottom = 0;
+
+	/* If we are generating a world, and waiting for a paint run, mark it here
+	 *  as done painting, so we can continue generating. */
+	if (IsGeneratingWorld() && IsGeneratingWorldReadyForPaint()) {
+		SetGeneratingWorldPaintStatus(false);
+	}
 }