Publish with Backpressure
Merge pull request #1784 from benjchristensen/publish-backpressure

Publish with Backpressure
Remove Multicast

The implementation is still there as `replay` is still using it, but the public API is removed.
Merge pull request #1786 from benjchristensen/1779-multicast

Remove Multicast
Remove *withIndex Operators

See https://github.com/ReactiveX/RxJava/issues/1782 -> Remove takeWhileWithIndex & skipWhileWithIndex
GroupedObservable.from/create

See https://github.com/ReactiveX/RxJava/issues/1668
Merge pull request #1787 from benjchristensen/1782-remove-withIndex

Remove *withIndex Operators
Merge pull request #1789 from benjchristensen/1668-groupedObservable

GroupedObservable.from/create