message: docs: add changelog for 4.1.0-beta.1
diff: +<a name="4.1.0-beta.1"></a>
  +# [4.1.0-beta.1](https://github.com/angular/angular/compare/4.1.0-beta.0...4.1.0-beta.1) (2017-04-12)
  +
  +
  +### Bug Fixes
  +
  +* **compiler:** fix inheritance for AOT with summaries ([#15583](https://github.com/angular/angular/issues/15583)) ([8ef621a](https://github.com/angular/angular/commit/8ef621a))
  +* **language-service:** avoid throwing exceptions when reporting metadata errors ([7764c5c](https://github.com/angular/angular/commit/7764c5c))
  +* **language-service:** detect when there isn't a tsconfig.json ([258d539](https://github.com/angular/angular/commit/258d539)), closes [#15874](https://github.com/angular/angular/issues/15874)
  +* **language-service:** improve resilience to incomplete information ([71a8627](https://github.com/angular/angular/commit/71a8627))
  +* **language-service:** initialize static reflector correctly ([fe0d02f](https://github.com/angular/angular/commit/fe0d02f)), closes [#15768](https://github.com/angular/angular/issues/15768)
  +* **language-service:** parse extended i18n forms ([bde9771](https://github.com/angular/angular/commit/bde9771))
  +* **language-service:** resolve any parameter types to any result ([5fbb0d0](https://github.com/angular/angular/commit/5fbb0d0))
  +* **router:** fix query param parsing ([a487563](https://github.com/angular/angular/commit/a487563))
  +* **router:** the preloader use the module from the loaded config ([6d12aa9](https://github.com/angular/angular/commit/6d12aa9))
  +* **tsc-wrapped:** ensure valid path separators in metadata ([96aa236](https://github.com/angular/angular/commit/96aa236))
  +
  +
  +### Features
  +
  +* **animations:** Update types for TypeScript nullability support ([38d75d4](https://github.com/angular/angular/commit/38d75d4)), closes [#15870](https://github.com/angular/angular/issues/15870)
  +* **benchpress:** Update types for TypeScript nullability support ([14669f2](https://github.com/angular/angular/commit/14669f2))
  +* **common:** Update types for TypeScript nullability support ([d8b73e4](https://github.com/angular/angular/commit/d8b73e4))
  +* **compiler:** Update types for TypeScript nullability support ([09d9f5f](https://github.com/angular/angular/commit/09d9f5f))
  +* **language-service:** Update types for TypeScript nullability support ([540581d](https://github.com/angular/angular/commit/540581d))
  +* Update types for TypeScript nullability support in examples ([6f5fccf](https://github.com/angular/angular/commit/6f5fccf))
  +
  +
  +
  <a name="4.0.2"></a>
  ## [4.0.2](https://github.com/angular/angular/compare/4.0.1...4.0.2) (2017-04-11)
  