allow to re-start arenas

src/balancing/BalancingWindow.h

@@ -33,12 +33,15 @@ private:
 
     struct ArenaEntry
     {
+        ArenaConfig config;
         std::unique_ptr<ArenaSimulation> simulation;
         std::thread worker;
         ArenaWidget* widget;
     };
 
     std::vector<ArenaEntry> m_arenas;
+    const GameConfig& m_gameConfig;
+    unsigned int m_nextSeed;
     QPushButton* m_startAllButton;
     QTimer* m_pollTimer;
 };