<a name="4.0.0-beta.2"></a>

* **compiler:** generate less code for bindings to DOM elements ([db49d42](https://github.com/angular/angular/commit/db49d42))

* **compiler:** generate proper reexports in `.ngfactory.ts` files to not need transitive deps for compiling `.ngfactory.ts` files. ([#13524](https://github.com/angular/angular/issues/13524)) ([9c69703](https://github.com/angular/angular/commit/9c69703)), closes [#12787](https://github.com/angular/angular/issues/12787)

* **router:** add an extra argument to CanDeactivate interface ([#13560](https://github.com/angular/angular/issues/13560)) ([69fa3bb](https://github.com/angular/angular/commit/69fa3bb)), closes [#9853](https://github.com/angular/angular/issues/9853)

* **common:** improve error message by adding a link to trackBy docs ([#13634](https://github.com/angular/angular/issues/13634)) ([6976903](https://github.com/angular/angular/commit/6976903))

* **common:** do not override locale provided on bootstrap ([#13654](https://github.com/angular/angular/issues/13654)) ([2dd6280](https://github.com/angular/angular/commit/2dd6280)), closes [#13607](https://github.com/angular/angular/issues/13607)

* **common:** allow null/undefined values for `NgForTrackBy` ([f88cd2f](https://github.com/angular/angular/commit/f88cd2f)), closes [#13641](https://github.com/angular/angular/issues/13641)

* **compiler:** don’t throw when using `ANALYZE_FOR_ENTRY_COMPONENTS` with user classes ([#13679](https://github.com/angular/angular/issues/13679)) ([7690d02](https://github.com/angular/angular/commit/7690d02)), closes [#13565](https://github.com/angular/angular/issues/13565)

* **compiler:** improve error message for undefined providers ([#13546](https://github.com/angular/angular/issues/13546)) ([6b02b80](https://github.com/angular/angular/commit/6b02b80)), closes [#10835](https://github.com/angular/angular/issues/10835)

* **compiler:** improve the error when template is not a string ([2c0c86e](https://github.com/angular/angular/commit/2c0c86e)), closes [#8708](https://github.com/angular/angular/issues/8708) [#13377](https://github.com/angular/angular/issues/13377)

* **compiler:** query `<template>` elements before their children. ([#13677](https://github.com/angular/angular/issues/13677)) ([7c21064](https://github.com/angular/angular/commit/7c21064)), closes [#13118](https://github.com/angular/angular/issues/13118) [#13167](https://github.com/angular/angular/issues/13167)

* **compiler:** throw an error for invalid provider ([#13544](https://github.com/angular/angular/issues/13544)) ([445ed43](https://github.com/angular/angular/commit/445ed43)), closes [#8870](https://github.com/angular/angular/issues/8870)

* **compiler:** allow "." in attribute selectors ([#13653](https://github.com/angular/angular/issues/13653)) ([881eb89](https://github.com/angular/angular/commit/881eb89)), closes [#13645](https://github.com/angular/angular/issues/13645)

* **core:** animations no longer silently exits if the element is not apart of the DOM ([#13763](https://github.com/angular/angular/issues/13763)) ([21030e9](https://github.com/angular/angular/commit/21030e9))

* **core:** animations should blend in all previously transitioned styles into next animation if interrupted ([#13148](https://github.com/angular/angular/issues/13148)) ([889b48d](https://github.com/angular/angular/commit/889b48d))

* **core:** remove reference to "Angular 2" in dev mode warning ([#13751](https://github.com/angular/angular/issues/13751)) ([c5c53f3](https://github.com/angular/angular/commit/c5c53f3))

* **forms:** Validators.required properly validate arrays ([#13362](https://github.com/angular/angular/issues/13362)) ([9898d8f](https://github.com/angular/angular/commit/9898d8f)), closes [#12274](https://github.com/angular/angular/issues/12274)

* **i18n:** parse ICU messages while normalizing templates ([e74d8aa](https://github.com/angular/angular/commit/e74d8aa))

* **language-service:** support TypeScript 2.1 ([#13655](https://github.com/angular/angular/issues/13655)) ([8063b0d](https://github.com/angular/angular/commit/8063b0d))

* **router:** fix lazy loaded module with wildcard route ([#13649](https://github.com/angular/angular/issues/13649)) ([0eca960](https://github.com/angular/angular/commit/0eca960)), closes [#12955](https://github.com/angular/angular/issues/12955)

* **router:** routerLink support of null ([#13380](https://github.com/angular/angular/issues/13380)) ([174334d](https://github.com/angular/angular/commit/174334d)), closes [#6971](https://github.com/angular/angular/issues/6971)

* **router:** update route snapshot before emit new values ([#13558](https://github.com/angular/angular/issues/13558)) ([07e0fce](https://github.com/angular/angular/commit/07e0fce)), closes [#12912](https://github.com/angular/angular/issues/12912)

* **testing:** improve misleading error message when don't call compileComponents ([#13543](https://github.com/angular/angular/issues/13543)) ([67380d4](https://github.com/angular/angular/commit/67380d4)), closes [#11301](https://github.com/angular/angular/issues/11301)

* **upgrade:** fix/improve support for lifecycle hooks ([#13020](https://github.com/angular/angular/issues/13020)) ([e5c4e58](https://github.com/angular/angular/commit/e5c4e58))

* **core**: `SimpleChange` now takes an additional argument that defines whether this is the first

change or not. This is a low profile API and we don't expect anyone to be affected by this change.

If you are impacted by this change please file an issue. ([465516b](https://github.com/angular/angular/commit/465516b))

Due to regression in the 2.3.0 release that was fixed by [#13464](https://github.com/angular/angular/pull/13464),

The >=2.3.1 compiler will issue is the following error if it encounters components compiled with 2.3.0: