Document Rx equivalents
First pass at a "Differences from Rx" document
Document high-level interface equivalence
Embolden the class names for better readability
Put notable method differences into a list
Put acronyms in parentheses
Merge branch 'master' into rx-differences
Use qualified names for IObserver methods
Remove parentheses from C# method names
Specify the overload of Merge that -flatten: corresponds to
Remove parentheses in standalone document too
Add -[RACCompoundDisposable removeDisposable:]
Allow nil in -removeDisposable:

This way, you can keep a disposable in a weak reference and not worry
about checking it before passing it in.
Remove recursive scheduling disposables when they're done
Remove -bind: disposables when done
Remove subscribeForever() disposables when done
Merge pull request #265 from github/rx-differences

Document major differences from Rx
Refactor RACSequenceExamples to use block arguments
Fix eager sequences test
Fix RACSequenceAdditionsSpec