(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/network/network_client.cpp

@@ -16,7 +16,6 @@
 #include "../command_func.h"
 #include "../console_func.h"
 #include "../variables.h"
-#include "../ai/ai.h"
 #include "../core/alloc_func.hpp"
 #include "../fileio_func.h"
 #include "../md5.h"
@@ -26,6 +25,7 @@
 #include "../company_func.h"
 #include "../company_base.h"
 #include "../company_gui.h"
+#include "../settings_type.h"
 #include "../rev.h"
 
 #include "table/strings.h"

src/network/network_gui.cpp

@@ -1170,8 +1170,8 @@ struct NetworkLobbyWindow : public Window {
 		const NetworkGameInfo *gi = &this->server->info;
 		int y = NET_PRC__OFFSET_TOP_WIDGET_COMPANY, pos;
 
-		/* Join button is disabled when no company is selected */
-		this->SetWidgetDisabledState(NLWW_JOIN, this->company == INVALID_COMPANY);
+		/* Join button is disabled when no company is selected and for AI companies*/
+		this->SetWidgetDisabledState(NLWW_JOIN, this->company == INVALID_COMPANY || GetLobbyCompanyInfo(this->company)->ai);
 		/* Cannot start new company if there are too many */
 		this->SetWidgetDisabledState(NLWW_NEW, gi->companies_on >= gi->companies_max);
 		/* Cannot spectate if there are too many spectators */

src/network/network_server.cpp

@@ -664,7 +664,7 @@ DEF_SERVER_RECEIVE_COMMAND(PACKET_CLIENT_JOIN)
 			}
 			break;
 		default: /* Join another company (companies 1-8 (index 0-7)) */
-			if (!IsValidCompanyID(playas)) {
+			if (!IsValidCompanyID(playas) || !IsHumanCompany(playas)) {
 				SEND_COMMAND(PACKET_SERVER_ERROR)(cs, NETWORK_ERROR_COMPANY_MISMATCH);
 				return;
 			}

src/network/network_type.h

@@ -48,6 +48,7 @@ typedef uint8 ClientIndex;
 struct NetworkCompanyStats {
 	uint16 num_vehicle[NETWORK_VEHICLE_TYPES];      ///< How many vehicles are there of this type?
 	uint16 num_station[NETWORK_STATION_TYPES];      ///< How many stations are there of this type?
+	bool ai;                                        ///< Is this company an AI
 };
 
 /** Some state information of a company, especially for servers */