Remove try/catch
Fixes #2020 - Race Condition in UIImageView+AFNetworking when called twice with the same URL
Revert "Remove try/catch"

This reverts commit c239e15ce51cd725e6645f519f0c759debc7b9fc.
Merge branch 'master' of git://github.com/AFNetworking/AFNetworking
Don't update NSProgress for data tasks

1. Progress is never returned by data task methods, only download methods. Those methods update the progress elsewhere so removing this shouldn't affect them.
2. The totalUnitCount is never being set during data tasks, so even if it was being returned, the NSProgress always reports a fractionCompleted of 0 right now.
3. There is a crash that occurs here rarely. My best guess is that the delegate is still being sent messages as it's being released.
[Issue #2032] Documenting change in behavior of NSOutputStream property
Merge branch 'master' of github.com:AFNetworking/AFNetworking
[Issue #2032] Only nil out outputStream property of connection operation if responseData is non-nil, meaning that no custom  was set
closes #2035
Update adn leaf cert
Merge pull request #2042 from carsonmcdonald/adncertupdate

Update adn leaf cert
Import UIRefreshControl+AFNetworking
Support NSSecureCoding in AFURLResponseSerialization
Support CGFLOAT_IS_DOUBLE  in AFImageResponseSerializer
[AFHTTPResponseSerializer] Use copy to ensure immutable types
Merge pull request #2045 from BB9z/UIRefreshControl

Import UIRefreshControl+AFNetworking
[Issue #2015][Issue #2040] Define AF_Require_noErr macro, to avoid compiler warning for __Require_noErr
Changing security policy to none, while new example endpoint is considered
Merge branch 'master' of github.com:AFNetworking/AFNetworking
Merge pull request #2037 from timbrah/master

closes #2035