Remove try/catch
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.
Merge branch 'master' of github.com:PadraigK/AFNetworking into PadraigK-master
[Issue #1675] Adding attemptsToRecreateUploadTasksForBackgroundSessions property
Merge branch 'master' of git://github.com/AFNetworking/AFNetworking
UIKit requires that the completionHandler for application:handleEventsForBackgroundURLSession:completionHandler be called on the main thread.

http://developer.apple.com/library/etc/redirect/xcode/ios/889e4b/documentation/Foundation/Reference/NSURLSessionDelegate_protocol/Reference/Reference.html
Adding tests for URLSession manager upload/download task progress
Making URLSession task progresses comply with NSProgress composition
Add an explanation of Reachability.
Remove empty line noise.
Update CONTRIBUTING.md
Extension for WebFrame loadRequest
UIImageView allows weaker serializer subclasses

Weakened serializer from subclasses of AFImageResponseSerializer to any
class conforming to AFURLResponseSerialization protocol.
This allows compound serialiers to be set for handling different image
types, like gifs and normal images.
Prevents NSNotification from firing twice, when the reachability status changes.
Merge pull request #2113 from SSA111/master

Prevents NSNotification from firing twice, when the reachability status ...
Adding explicit @synthesize for streamStatus & streamError properties

Signed-off-by: Mattt Thompson <m@mattt.me>
Merge branch 'master' of github.com:AFNetworking/AFNetworking
Squashed commit of the following:

commit c5463a0dfdf501425354ca02e774c79b809df582
Author: Mattt Thompson <m@mattt.me>
Date:   Thu Jun 5 17:06:54 2014 -0700

    Refactoring configuration of callback queue / group

commit 69d04fe8a44eedfcb0b96cba5931f8599c2c49b5
Merge: f042803 56c2ba1
Author: Mattt Thompson <m@mattt.me>
Date:   Thu Jun 5 17:02:42 2014 -0700

    Merge branch 'master' of github.com:robertmryan/AFNetworking into robertmryan-master

commit 56c2ba124d7d782d145a300bc4a72d20eb9a6c7f
Author: robertmryan <robert.ryan@mindspring.com>
Date:   Sun May 25 09:28:01 2014 -0400

    Correct location of completionQueue/completionGroup properties in header

commit 96ce766fc2687e7c2bfff41e41e2d91b4fee8228
Author: robertmryan <robert.ryan@mindspring.com>
Date:   Sun May 25 09:21:25 2014 -0400

    Add `completionQueue` and `completionGroup` properties to `AFHTTPRequestOperationManager`, which will be supplied to `AFHTTPRequestOperation` objects.