Netflix/RxJava — pull request #502 by benjchristensen (2013-11-20 00:31:12+00:00)
Title: Fix ObserveOn and add ParallelMerge Scheduler overload

- ObserveOn was not correctly recursing when the source was async. It would create a new scheduler (i.e. a new thread) each time.
- Also added unit tests to ParallelMerge