(svn r15027) -Merge: tomatos and bananas left to be, here is NoAI for all to see.

NoAI is an API (a framework) to build your own AIs in. See:
   http://wiki.openttd.org/wiki/index.php/AI:Main_Page
 With many thanks to:
  - glx and Rubidium for their syncing, feedback and hard work
  - Yexo for his feedback, patches, and AIs which tested the system very deep
  - Morloth for his feedback and patches
  - TJIP for hosting a challenge which kept NoAI on track
  - All AI authors for testing our AI API, and all other people who helped in one way or another
-Remove: all old AIs and their cheats/hacks

src/genworld.cpp

@@ -25,6 +25,7 @@
 #include "settings_type.h"
 #include "newgrf_storage.h"
 #include "water.h"
+#include "blitter/factory.hpp"
 #include "tilehighlight_func.h"
 #include "saveload/saveload.h"
 
@@ -298,7 +299,7 @@ void GenerateWorld(GenerateWorldMode mode, uint size_x, uint size_y)
 		_gw.thread = NULL;
 	}
 
-	if (_network_dedicated ||
+	if (BlitterFactoryBase::GetCurrentBlitter()->GetScreenDepth() == 0 ||
 	    (_gw.thread = ThreadObject::New(&_GenerateWorld, NULL)) == NULL) {
 		DEBUG(misc, 1, "Cannot create genworld thread, reverting to single-threaded mode");
 		_gw.threaded = false;