ReactiveX/RxJava — pull request #1623 by zsxwing (2014-08-22 09:32:45+00:00)
Title: RxScala: Add more operators to match RxJava

including `window(span, shift, unit, count, scheduler)`, `cache(Int)`, `groupBy[K, V](keySelector: T => K, valueSelector: T => V)`, `compose`, `onBackpressureBuffer`, `onBackpressureDrop`, `collect` and `using`.

/cc @headinthebox, @samuelgruetter