Call super copyWithZone: in subclasses.

By not calling the superclass' implementation, we end up not actually
copying over all the properties from the superclass. In this case, if we
call -copy on an instance of an AFJSONRequestSerializer, the headers for
the serializer are not copied over (as well as anything else that was
changed in the AFHTTPRequestSerializer implementation).
Tried to make requirements clearer.
Merge pull request #2067 from getaaron/requirements-README-update

Tried to make requirements clearer.
[Issue #2067] Minor copy editing and formatting
Removing remarks about 2.0
Update README.md
Update README.md
Update README.md
failure call back check uiImageView operation request url

the [operation.request URL] always equal urlRequest  . failure call
back block check uiImageView requestOperation request url
Squashed commit of the following:

commit f6d5e3c2dd4bd1280e79133b617bc523574c2ded
Author: Mattt Thompson <m@mattt.me>
Date:   Sat May 17 11:57:53 2014 -0700

    Refactoring network AFNetworkActivityIndicatorManager tests

commit dc9fc2d99615dbb5314627cfafd57138d539e8d2
Author: Dave Weston <dweston@yammer-inc.com>
Date:   Tue Apr 15 12:18:21 2014 -0700

    Add tests around AFNetworkActivityIndicatorManager
Removing unnecessary default operation response serializer setters
Refactoring serialization tests to be split up into request / response serializer tests

Refactoring serialization test cases to take advantage of setUp
Squashed commit of the following:

commit 3054fd6f09b8bb2caef04a2aab97aebe4f102ce6
Author: Mattt Thompson <m@mattt.me>
Date:   Sat May 17 12:25:08 2014 -0700

    Minor refactoring of userInfo into separate declaration

commit 936ccb74eea302e4ee9b174fd80a8b72d62367bb
Author: Kyle Fuller <inbox@kylefuller.co.uk>
Date:   Sat May 17 12:23:51 2014 -0700

    Setting notification object to self

commit b9b6e6148a8ed5698daae9696d10656af4a39763
Merge: a2040b5 509fedb
Author: Mattt Thompson <m@mattt.me>
Date:   Sat May 17 12:21:24 2014 -0700

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

commit 509fedbfb56c1ff2f8741b1b3d25198b4a018fd1
Author: Jason Pepas <jpepas@uship.com>
Date:   Thu May 15 15:55:40 2014 -0500

    Adding notification for initial change from AFNetworkReachabilityStatusUnknown to any other state.
Merge pull request #2062 from streeter/copywithzone-should-call-super

Call super copyWithZone: in subclasses.
Merge pull request #2070 from sipdar/master

image Download failure call back block check uiImageView operation request url equal