Tcod-ecs

Added

- Added `WorldQuery.get_entities` for returning query results as a set.

Fixed

- Removed an optimization which would check the equality of component values, since this would fail when comparing some types such as NumPy arrays.
- Removed unintentional iteration behavior from `World`. https://github.com/HexDecimal/python-tcod-ecs/issues/8

Fixed

- Relation component lookup tables were replacing previous entries instead of adding to them.
- Relation ellipsis lookup tables were discarding entities which still had a relevant relation.

Added

- `tcod.ecs.typing.ComponentKey` is now stable.
- Can now register a callback to be called on component changes.

Fixed

- Fixed stale caches for relation components.

Fixed

- Unpickled worlds had reversed relations from what were saved.

Added

- `Entity.relation_components` now has `MutableMapping` functionality.
- You can now set the value of `Entity.relation_components[component_key] = {target: component}`.
- Added the `Entity.clear` method which effectively deletes an entity by removing its components/tags/relations.
This does not delete relations targeting the cleared entity.

Added

- Now supports giving a query to another relation query, allowing conditional and chained relation queries. https://github.com/HexDecimal/python-tcod-ecs/issues/1