(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

command.c

@@ -10,6 +10,7 @@
 #include "player.h"
 #include "network.h"
 #include "variables.h"
+#include "genworld.h"
 
 const char* _cmd_text = NULL;
 
@@ -456,7 +457,7 @@ bool DoCommandP(TileIndex tile, uint32 p1, uint32 p2, CommandCallback *callback,
 	_docommand_recursive = 1;
 
 	// cost estimation only?
-	if (_shift_pressed && IsLocalPlayer() && !(cmd & (CMD_NETWORK_COMMAND | CMD_SHOW_NO_ERROR))) {
+	if (!IsGeneratingWorld() && _shift_pressed && IsLocalPlayer() && !(cmd & (CMD_NETWORK_COMMAND | CMD_SHOW_NO_ERROR))) {
 		// estimate the cost.
 		res = proc(tile, flags, p1, p2);
 		if (CmdFailed(res)) {