Removed local SerialSubscription isUnsubscribed implementation since underlying subscription now implements it.
Observable.from with scheduler
Observable.from with scheduler
Fixed blocking test in ObservableWindowTest
Added: BO.Latest, fixed: BO.next, BO.mostRecent, BO.toIterable
Fixes based on @zsxwing's suggestions.
Increased time delay in test.
Fixed issue #595 about null in toList operator
Operators: switchCase (Case), ifThen (If), doWhile (DoWhile), WhileDo (While)
Operators DelaySubscription, TakeLast w/ time, TakeLastBuffer
Fixed the blocking/non-blocking first
Add MSDN links
Mark takeFirst deprecated
Implement the blocking/non-blocking single, singleOrDefault, first, firstOrDefault, last, lastOrDefault
Fix the unit tests in groovy and kotlin
Remove volatile
BooleanSubscription: Add Action Support
Remove Unnecessary Subscription

- be explicit for error case in JoinObserver
Code Reformatting
Missing fixes from the subject rewrite.
Refactor RefCountSubscription

- simplified logic
- remove unnecessary busy spins and state changes