ECS library

• A ComponentRegistry where Component's class declaration is registered beforehand.
• A Component has properties, which is a plain key => value data store.
  • A Component can belong to a "components group" via ComponentRegistry::registerComponentGroup.
• An Entity can have multiple Components attached to it via a bitmask.
• A System can receive a Query that is based on Entities that have specific Components.
• A World class which ties everything together and also contains a game loop.