Tcod-ecs

Changed

- The type returned by `World.Q` has been renamed from `tcod.ecs.Query` to `tcod.ecs.query.WorldQuery`.
- Serialization format updated.

Performance

- Added a simple query cache.
A query is automatically cached until any of the components/tags/relations it depends on have changed.

Changed

- Serialization format updated, older versions will not be able to unpickle this version.
- Reduced the size of the pickled World.

Fixed

- Missing components in `Entity.components` now returns the missing key in the KeyError exception instead of the entity.
- Backwards relations for querying were not cleared on relation deletions.

Added

- `Entity.components` now supports the `|=` assignment operator.

Added

- `Entity.tags` now supports the `|=` and `-=` assignment operators.

Changed

- Warn if a string is passed directly as a tags parameter, which might cause unexpected behavior.
- `Entity.relation_tags` has been renamed to `Entity.relation_tag`.

Deprecated

- Deprecated the renamed attribute `Entity.relation_tag`.

Changed

- `World.new_entity` can now take a `Mapping` as the `components` parameter.

Deprecated

- Implicit keys for components have been deprecated in all places.
- The names feature has been deprecated.
- `Entity.components.by_name_type` has been deprecated.