Fix commander appearing in battles while dead

lib/BattleState.cpp

@@ -499,7 +499,7 @@ BattleInfo * BattleInfo::setupBattle( int3 tile, ETerrainType terrain, BFieldTyp
 	//adding commanders
 	for (int i = 0; i < 2; ++i)
 	{
-		if (heroes[i] && heroes[i]->commander)
+		if (heroes[i] && heroes[i]->commander && heroes[i]->commander->alive)
 		{
 			CStack * stack = curB->generateNewStack (*heroes[i]->commander, !i, SlotID::COMMANDER_SLOT_PLACEHOLDER,
 				creatureBank ? commanderBank[i] : commanderField[i]);

lib/CCreatureSet.h

@@ -102,7 +102,7 @@ public:
 	//TODO: what if Commander is not a part of creature set?
 
 	//commander class is determined by its base creature
-	ui8 alive;
+	bool alive;
 	ui8 level; //required only to count callbacks
 	std::string name; // each Commander has different name
 	std::vector <ui8> secondarySkills; //ID -> level