Fixes problems with windows:

- Changed cPlayer:OpenWindow to accept a ref, tolua adds a nil check
- Close open lua window in destructor, to avoid dangling pointers

src/BlockEntities/BeaconEntity.cpp

@@ -297,7 +297,7 @@ bool cBeaconEntity::UsedBy(cPlayer * a_Player)
 		// if (a_Player->GetWindow() != Window)
 		// -> Because mojang doesn't send a 'close window' packet when you click the cancel button in the beacon inventory ...
 		{
-			a_Player->OpenWindow(Window);
+			a_Player->OpenWindow(*Window);
 		}
 	}
 	return true;

src/BlockEntities/BrewingstandEntity.cpp

@@ -65,7 +65,7 @@ bool cBrewingstandEntity::UsedBy(cPlayer * a_Player)
 	{
 		if (a_Player->GetWindow() != Window)
 		{
-			a_Player->OpenWindow(Window);
+			a_Player->OpenWindow(*Window);
 		}
 	}
 

src/BlockEntities/ChestEntity.cpp

@@ -101,7 +101,7 @@ bool cChestEntity::UsedBy(cPlayer * a_Player)
 	{
 		if (a_Player->GetWindow() != Window)
 		{
-			a_Player->OpenWindow(Window);
+			a_Player->OpenWindow(*Window);
 		}
 	}
 

src/BlockEntities/DropSpenserEntity.cpp

@@ -153,7 +153,7 @@ bool cDropSpenserEntity::UsedBy(cPlayer * a_Player)
 	{
 		if (a_Player->GetWindow() != Window)
 		{
-			a_Player->OpenWindow(Window);
+			a_Player->OpenWindow(*Window);
 		}
 	}
 	return true;

src/BlockEntities/EnderChestEntity.cpp

@@ -66,7 +66,7 @@ bool cEnderChestEntity::UsedBy(cPlayer * a_Player)
 	{
 		if (a_Player->GetWindow() != Window)
 		{
-			a_Player->OpenWindow(Window);
+			a_Player->OpenWindow(*Window);
 		}
 	}
 	return true;

src/BlockEntities/FurnaceEntity.cpp

@@ -69,7 +69,7 @@ bool cFurnaceEntity::UsedBy(cPlayer * a_Player)
 	{
 		if (a_Player->GetWindow() != Window)
 		{
-			a_Player->OpenWindow(Window);
+			a_Player->OpenWindow(*Window);
 		}
 	}
 

src/BlockEntities/HopperEntity.cpp

@@ -95,7 +95,7 @@ bool cHopperEntity::UsedBy(cPlayer * a_Player)
 	{
 		if (a_Player->GetWindow() != Window)
 		{
-			a_Player->OpenWindow(Window);
+			a_Player->OpenWindow(*Window);
 		}
 	}