Refactor EntityList and prevent World to invalidate its own handles between updates

SDK/src/NDK/EntityList.cpp

@@ -0,0 +1,14 @@
+// Copyright (C) 2017 Jérôme Leclercq
+// This file is part of the "Nazara Development Kit"
+// For conditions of distribution and use, see copyright notice in Prerequesites.hpp
+
+#include <NDK/EntityList.hpp>
+#include <NDK/World.hpp>
+
+namespace Ndk
+{
+	const EntityHandle& EntityList::iterator::operator*() const
+	{
+		return m_list->GetWorld()->GetEntity(static_cast<EntityId>(m_nextEntityId));
+	}
+}