(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/road_cmd.cpp

@@ -925,10 +925,7 @@ static CommandCost ClearTile_Road(TileIndex tile, byte flags)
 
 			/* Clear the road if only one piece is on the tile OR the AI tries
 			 * to clear town road OR we are not using the DC_AUTO flag */
-			if ((CountBits(b) == 1 && GetRoadBits(tile, ROADTYPE_TRAM) == ROAD_NONE) ||
-			    ((flags & DC_AI_BUILDING) && GetOtherRoadBits(tile, ROADTYPE_ROAD) == ROAD_NONE && IsRoadOwner(tile, ROADTYPE_ROAD, OWNER_TOWN)) ||
-			    !(flags & DC_AUTO)
-				) {
+			if ((CountBits(b) == 1 && GetRoadBits(tile, ROADTYPE_TRAM) == ROAD_NONE) || !(flags & DC_AUTO)) {
 				RoadTypes rts = GetRoadTypes(tile);
 				CommandCost ret(EXPENSES_CONSTRUCTION);
 				for (RoadType rt = ROADTYPE_ROAD; rt < ROADTYPE_END; rt++) {