Fixed linux compilation.

src/achievements/achievement.cpp

@@ -22,14 +22,14 @@
 #include "achievements/achievement_info.hpp"
 #include "guiengine/dialog_queue.hpp"
 #include "states_screens/dialogs/notification_dialog.hpp"
-#include "io/xml_writer.hpp"
 #include "utils/log.hpp"
 #include "utils/translation.hpp"
 
 
+#include <assert.h>
+#include <fstream>
 #include <sstream>
 #include <stdlib.h>
-#include <assert.h>
 
 // ============================================================================
 Achievement::Achievement(const AchievementInfo * info)

src/challenges/challenge.cpp

@@ -22,7 +22,6 @@
 
 #include "challenges/challenge_data.hpp"
 #include "io/xml_node.hpp"
-#include "io/xml_writer.hpp"
 #include "karts/kart_properties_manager.hpp"
 #include "karts/kart_properties.hpp"
 #include "race/grand_prix_manager.hpp"

src/challenges/unlock_manager.cpp

@@ -369,7 +369,7 @@ bool UnlockManager::deleteSlotsIfNeeded()
         if (!found)
         {
 #ifdef DEBUG
-            printf("Deleting gameslot %s, no player found.\n",
+            printf("Deleting gameslot %d, no player found.\n",
                     it->second->getPlayerID());
 #endif
             // Iterators aren't invalidated this way