Add -[NSUserDefaults rac_channelTerminalForKey:]
Remove unused variable
Don't send signals back when sent from the other side
Style: spaces around BOOL
Expect BOOLs, not NSNumbers
Add NSUserDefaults+RACSupport.h to ReactiveCocoa.h
Merge pull request #1018 from ReactiveCocoa/user-defaults

Add an extension to `NSUserDefaults` to create a channel for a key