ReactiveX/RxJava — pull request #1694 by davidmoten (2014-09-21 21:39:34+00:00)
Title: OnSubscribeRefCount rewrite to handle synchronous source #1688

Rewrite of ```OnSubscribeRefCount``` because original didn't handle synchronous source (#1688) and as far as I could see the original was fundamentally broken by this use case. Please note also includes a fix in ```OperatorMulticast``` where a null check was required. I've done the rewrite using locks rather than submit a lock-free version just to ensure that the approach is valid with the experts first.