ReactiveCocoa/ReactiveCocoa — pull request #582 by jspahrsummers (2013-06-13 23:41:59+00:00)
Title: Fix subscribers receiving events even after subscription disposal

This bug was really nasty. See 1d53d7ff6b19daa68709159c0fa7ee9e484b1ebb for a reproduction case.

It was somewhat tricky to fix, because a single `` must support being subscribed to multiple signals. The workaround is a new, private `RACPassthroughSubscriber` class, which we can manually shut off once the "original" subscription is disposed.