2.1.4 release preparation

[akarnokd]

Version 2.1.4 - September 22, 2017 (Maven)

API changes

• Pull 5568: Add BaseTestConsumer.assertValuesOnly.
• Pull 5582: Add Maybe.switchIfEmpty(Single).
• Pull 5590: Add LambdaConsumerIntrospection for detecting the lack of onError callback in subscribe() calls.

Documentation changes

• Pull 5578: Add NullPointerException comment to some Single operators.
• Pull 5600: Updating JavaDoc with correct return types of Single in some Observable operators.

Bugfixes

• Pull 5560: Fix Observable.combineLatestDelayError sync initial error not emitting.
• Pull 5594: Fix BaseTestConsumer.assertValueSequence reversed error message.
• Pull 5609: Fix Observable.concatMapEager queueing of source items.

Other

• Pull 5586: fix Single.timeout unnecessary dispose calls.

[akarnokd]

Closing via 2.1.4.