1.x: release 1.1.1 preparations

Author: akarnokd

CHANGES.md

@@ -1,5 +1,75 @@
 # RxJava Releases #
 
+### Version 1.1.1 - January 22, 2016 ([Maven](http://search.maven.org/#artifactdetails%7Cio.reactivex%7Crxjava%7C1.1.1%7C))
+
+#### The new `Completable` class
+
+  - [Pull 3444](https://github.com/ReactiveX/RxJava/pull/3444) Completable class to support valueless event composition + tests
+
+##### What is this Completable class?
+
+We can think of a `Completable` object as a stripped version of `Observable` where only the terminal events, `onError` and `onCompleted` are ever emitted; they may look like an `Observable.empty()` typified in a concrete class but unlike `empty()`, `Completable` is an active class. `Completable` mandates side effects when subscribed to and it is its main purpose indeed. `Completable` contains some deferred computation with side effects and only notifies about the success or failure of such computation.
+
+Similar to `Single`, the `Completable` behavior can be emulated with `Observable<?>` to some extend, but many API designers think codifying the valuelessness in a separate type is more expressive than messing with wildcards (and usually type-variance problems) in an `Observable` chain.
+
+`Completable` doesn't stream a single value, therefore, it doesn't need backpressure, simplifying the internal structure from one perspective, however, optimizing these internals requires more lock-free atomics knowledge in some respect.
+
+
+##### Hello World!
+
+Let's see how one can build a (side-effecting) Hello World `Completable`:
+
+```java
+Completable.fromAction(() -> System.out.println("Hello World!"))
+.subscribe();
+```
+
+Quite straightforward. We have a set of `fromXXX` method which can take many sources: `Action`, `Callable`, `Single` and even `Observable` (stripping any values generated by the latter 3 of course). On the receiving end, we have the usual subscribe capabilities: empty, lambdas for the terminal events, a `rx.Subscriber` and a `rx.Completable.CompletableSubscriber`, the main intended receiver for `Completable`s.
+
+##### Further reading
+
+  - [The new Completable API - part 1](http://akarnokd.blogspot.hu/2015/12/the-new-completable-api-part-1.html)
+  - [The new Completable API - part 2](http://akarnokd.blogspot.hu/2015/12/the-new-completable-api-part-2-final.html)
+
+#### API enhancements
+
+  - [Pull 3434](https://github.com/ReactiveX/RxJava/pull/3434) Add Single.doAfterTerminate()
+  - [Pull 3447](https://github.com/ReactiveX/RxJava/pull/3447) operator DelaySubscription with plain Observable
+  - [Pull 3489](https://github.com/ReactiveX/RxJava/pull/3489) Rename cache(int) to cacheWithCapacityHint(int)
+  - [Pull 3539](https://github.com/ReactiveX/RxJava/pull/3539) Add Single.zip() for Iterable of Singles
+  - [Pull 3562](https://github.com/ReactiveX/RxJava/pull/3562) Add Single.doOnUnsubscribe()
+  - [Pull 3566](https://github.com/ReactiveX/RxJava/pull/3566) Deprecate Observable.finallyDo() and add Observable.doAfterTerminate() instead
+  - [Pull 3567](https://github.com/ReactiveX/RxJava/pull/3567) Implemented Observable#toCompletable
+  - [Pull 3570](https://github.com/ReactiveX/RxJava/pull/3570) Implemented Completable#andThen(Observable)
+  
+#### API deprecations
+
+  - `cache(int)` via #3489, replaced by `cacheWithCapacityHint(int)`
+  - `finallyDo(Action0)` via #3566, replaced by `doAfterTerminate(Action0)`
+  
+### Performance improvements
+
+  - [Pull 3477](https://github.com/ReactiveX/RxJava/pull/3477) add a source OnSubscribe which works from an array directly
+  - [Pull 3579](https://github.com/ReactiveX/RxJava/pull/3579) No more need to convert Singles to Observables for Single.zip()
+  - [Pull 3587](https://github.com/ReactiveX/RxJava/pull/3587) Remove the need for javac to generate synthetic methods
+  - [Pull 3614](https://github.com/ReactiveX/RxJava/pull/3614) just() now supports backpressure
+  
+#### Bugfixes
+
+  - [Pull 3428](https://github.com/ReactiveX/RxJava/pull/3428) GroupBy backpressure fix
+  - [Pull 3454](https://github.com/ReactiveX/RxJava/pull/3454) fix: bounded replay() not requesting enough for latecommers
+  - [Pull 3467](https://github.com/ReactiveX/RxJava/pull/3467) compensate for drastic clock drifts when scheduling periodic tasks
+  - [Pull 3555](https://github.com/ReactiveX/RxJava/pull/3555) fix toMap and toMultimap not handling exceptions of the callbacks
+  - [Pull 3585](https://github.com/ReactiveX/RxJava/pull/3585) fix Completable.using not disposing the resource if the factory crashes during the subscription phase
+  - [Pull 3588](https://github.com/ReactiveX/RxJava/pull/3588) Fix the initialization order in GenericScheduledExecutorService
+  - [Pull 3630](https://github.com/ReactiveX/RxJava/pull/3630) ConcatMapEager allow nulls from inner Observables.
+  - [Pull 3637](https://github.com/ReactiveX/RxJava/pull/3637) handle predicate exceptions properly in skipWhile
+  - [Pull 3638](https://github.com/ReactiveX/RxJava/pull/3638) fix error handling in OperatorDistinctUntilChanged
+  - [Pull 3639](https://github.com/ReactiveX/RxJava/pull/3639) fix error handling in onBackpressureBuffer
+  - [Pull 3640](https://github.com/ReactiveX/RxJava/pull/3640) fix error handling in onBackpressureDrop
+  - [Pull 3644](https://github.com/ReactiveX/RxJava/pull/3644)fix SyncOnSubscribe not signalling onError if the generator crashes
+  - [Pull 3645](https://github.com/ReactiveX/RxJava/pull/3645)fix Amb sharing the choice among all subscribers
+
 ### Version 1.1.0 – December 2 2015 ([Maven Central](http://search.maven.org/#artifactdetails%7Cio.reactivex%7Crxjava%7C1.1.0%7C)) ###
 
 * [Pull 3550] (https://github.com/ReactiveX/RxJava/pull/3550) Public API changes for 1.1.0 release