specs 0.11.0

Specs is an Entity-Component System library written in Rust.
Documentation
## 0.11 (alpha)

* Improve docs, book and examples ([#278], [#281], [#283], [#285], [#296], [#313], [#316], [#322], [#350], [#356], [#363])
* Add `StorageEntry` for easier handling of inserting/removing component ([#274])
* Add `EntityBuilder::marked` convenience method ([#287])
* Add `saveload` module for easy entity serialization ([#275], [#337])
* Add `nightly` feature flag for unstable features. ([#290])
* Add `TrackedStorage`, a more ergonomic variant to `FlaggedStorage` ([#291])
* Exclusive/mutable aliasing for getting an `EntityBuilder` to prevent unsafety. ([#294])
* Add `Bundle` for registering multiple resources and components at once. ([#296])
* Add `get()` method to `Join` for retrieving a single entities component in bulk. ([#299])
* Implementations of `Join` for owned `BitSet`s, including `AtomicBitset`. ([#303])
* Remove `FlaggedStorage` (new storage uses the same name) and `TrackedStorage` in favor of the new `Tracked` api. ([#305])
* Add `prelude` module for commonly used structures and traits. ([#305])
* Add `LazyBuilder` for easier entity construction in systems. ([#320])
* Replace `Entry` with `PairedStorage` to prevent runtime checks for `RestrictedStorage`. ([#324])
* Deprecate `check()` which hides a possibly expensive clone. ([#326])
* Add `ChangeSet` for easy application to components. ([#344])
* Use criterion.rs for benchmarks ([#348])
* Update to rayon 1.0 ([#352])
* Add `World::system_data` method ([#369])
* BREAKING: Change the way resources are handled (see below) ([shred#77])
* Export all items currently in prelude in the root of the crate ([#394])
* If an EntityBuilder drops before being built the entity will now be deleted on maintain ([#394])
* Removed some redundancy in documentation ([#394])

There is one bigger breaking change in this release. Almost all`Fetch` / `FetchMut` types need to be replaced
with `Read` / `Write`. Both require the resource to implement `Default`, because now the resources can be
added to the world automatically. If you want to make the resource optional and you don't have a sensible
default, `Option<Read>` / `Option<Write>` can be used. If you absolutely need the resource and it doesn't
work without, use `ReadExpect` which will panic in case the resource does not exist (that's the same
behavior as before).

[#274]: https://github.com/slide-rs/specs/pull/274
[#275]: https://github.com/slide-rs/specs/pull/275
[#278]: https://github.com/slide-rs/specs/pull/278
[#281]: https://github.com/slide-rs/specs/pull/281
[#283]: https://github.com/slide-rs/specs/pull/283
[#285]: https://github.com/slide-rs/specs/pull/285
[#287]: https://github.com/slide-rs/specs/pull/287
[#290]: https://github.com/slide-rs/specs/pull/290
[#291]: https://github.com/slide-rs/specs/pull/291
[#294]: https://github.com/slide-rs/specs/pull/294
[#296]: https://github.com/slide-rs/specs/pull/296
[#297]: https://github.com/slide-rs/specs/pull/297
[#299]: https://github.com/slide-rs/specs/pull/299
[#303]: https://github.com/slide-rs/specs/pull/303
[#305]: https://github.com/slide-rs/specs/pull/305
[#313]: https://github.com/slide-rs/specs/pull/313
[#316]: https://github.com/slide-rs/specs/pull/316
[#320]: https://github.com/slide-rs/specs/pull/320
[#322]: https://github.com/slide-rs/specs/pull/322
[#324]: https://github.com/slide-rs/specs/pull/324
[#326]: https://github.com/slide-rs/specs/pull/326
[#337]: https://github.com/slide-rs/specs/pull/337
[#344]: https://github.com/slide-rs/specs/pull/344
[#348]: https://github.com/slide-rs/specs/pull/348
[#350]: https://github.com/slide-rs/specs/pull/350
[#352]: https://github.com/slide-rs/specs/pull/352
[#356]: https://github.com/slide-rs/specs/pull/356
[#363]: https://github.com/slide-rs/specs/pull/363
[#369]: https://github.com/slide-rs/specs/pull/369
[#394]: https://github.com/slide-rs/specs/pull/394

[shred#77]: https://github.com/slide-rs/shred/pull/77

## 0.10.0

* Separate `CheckStorage` into two variants and fix soundness issues ([#203])
* Fix `Merge` system and add test for it ([#243], [#248])
* Add more examples, docs, tests, benchmarks ([#249], [#251], [#254], [#256], [#258])
* Use `Result`s to make Specs more robust ([#260])
* Check code coverage with cargo-travis ([#265])
* Make `common::Errors` atomic and more convenient ([#255], [#262])
* Add `World::delete_all` to clear the world ([#257])
* Fix insertion into occupied `NullStorage` entry ([#269])
* Add `Storage::drain` method ([#273])

[#203]: https://github.com/slide-rs/specs/pull/203
[#243]: https://github.com/slide-rs/specs/pull/243
[#248]: https://github.com/slide-rs/specs/pull/248
[#249]: https://github.com/slide-rs/specs/pull/249
[#251]: https://github.com/slide-rs/specs/pull/251
[#254]: https://github.com/slide-rs/specs/pull/254
[#255]: https://github.com/slide-rs/specs/pull/255
[#256]: https://github.com/slide-rs/specs/pull/256
[#257]: https://github.com/slide-rs/specs/pull/257
[#258]: https://github.com/slide-rs/specs/pull/258
[#260]: https://github.com/slide-rs/specs/pull/260
[#262]: https://github.com/slide-rs/specs/pull/262
[#265]: https://github.com/slide-rs/specs/pull/265
[#273]: https://github.com/slide-rs/specs/pull/273

## 0.9.3

* Add `specs-derive` crate, custom `#[derive]` for components ([#192])
* Add lazy updates: insert and remove components, execute closures on world ([#214], [#221])

[#192]: https://github.com/slide-rs/specs/pull/192
[#214]: https://github.com/slide-rs/specs/pull/214
[#221]: https://github.com/slide-rs/specs/pull/221

## 0.9.2
* Fixed grammar in book ([#198])
* Better docs for `World` and better panic message ([#199])
* Add support for Emscripten ([#205])
* Change examples to use `FooStorage<Self>` and destructure system data in method head ([#206])
* `AntiStorage` for `CheckStorage` ([#208])
* Integrate futures by introducing a `common` module ([#209])

[#198]: https://github.com/slide-rs/specs/pull/198
[#199]: https://github.com/slide-rs/specs/pull/199
[#205]: https://github.com/slide-rs/specs/pull/205
[#206]: https://github.com/slide-rs/specs/pull/206
[#208]: https://github.com/slide-rs/specs/pull/208
[#209]: https://github.com/slide-rs/specs/pull/209
[#214]: https://github.com/slide-rs/specs/pull/214