Treat project files as binary
Add Cedar
Remove extraneous whitespace
Add AFURLSession class

This is a subclass of NSURLSession that does not change anything about,
or add anything to, the superclass.  Its purpose is as an overridable
shim that we can later use to enable testing.
Add first specs for AFURLSessionManager
Convert AFURLSession to an NSProxy
Add factory method to create NSURLSession
Add NSURLSessionDataTask -cancel spec behavior
Data tasks may receive responses in specs
Data tasks may receive data in specs
Data tasks may complete in specs
Data task helper method for completing requests
Test AFURLSessionManager delegates to session
Session may invalidate in specs
Tasks receive and record auth challenges in specs
Eliminate AFURLSession public class

This restores the AFURLSessionManager to its original state, with no
code changes and no factory methods for the session.
Extract NSURLSessionTask+Spec base class