Hide ChainedSubscription
Merge pull request #1309 from benjchristensen/subscriber-subscription

Hide ChainedSubscription/SubscriptionList from Public API
[Gradle Release Plugin] - pre tag commit:  '0.19.0'.
[Gradle Release Plugin] - new version commit:  '0.19.1-SNAPSHOT'.
0.19.0
Add onErrorFlatMap to RxScala
Add nest to RxScala
Add flatten variant to RxScala
Add switchMap to RxScala
Add retry variant to RxScala
Add error variant to RxScala
Add foreach to RxScala
Add combineLatest variant to RxScala
Add orElse to RxScala
Update CompletenessTest.scala
Add groupByUntil variant to RxScala
Add groupJoin to RxScala
Add pivot to RxScala
Add longCount to RxScala
Add toMultimap to RxScala