Fix warnings.
Methods will removed.
Various new methods.
Code improvements.
Add an old version of NSObject+RACKVOWrapper from GitHub’s ReactiveCocoa.
Update EXTScope, EXTKeyPathCoding. Remove EXTSwizzle.
New macros to detect iOS version.
dout 2.4.
New RF_GCD_STRONG and RF_GCD_WEAK.
Change UIAlertView, UINavigationController and UIResponder category included by default.
New RFDefineConstString().
Fix warnings.
Update unit test project.