2.5.3
Updating copyright year
Added guard to unsupported features of iOS 8 extensions
[Issue #2617] Fixing leak for addObserver:...:withBlock:
Merge pull request #2514 from Maxim-38RUS-Zabelin/master
A very minor typo in the docs for UIImageView+AFNetworking.h
Import UIRefreshControl+AFNetworking
fix a typo in comment
Refactor state of refresh control using task
fix UIWebView+AFNetworking crash