[Issue #737] Updating default Accept-Language header value in AFHTTPClient
Revert "Fixing warning caused by default statement in switch statement that covered all enumeration values"

This reverts commit b5c48f13a1d42952da78ab3027b7d804048f525b.
Fix  [Issue #751]
Serialize calls to responseJSON using a lock.

AFJSONRequestOperation's completion path calls `responseJSON` from a
processing queue.  Because `responseJSON` "lazily" deserializes the
response data into a JSON object, it needs to be protected against
concurrent access from other queues (threads).

For example, `AFNetworkingOperationDidFinishNotification` is posted
when the operation finishes but perhaps before that processing queue
has finishing executing.  Notification observers who also access
`responseJSON` end up in a race with that queue that often leads to a
crash.

We reuse the existing lock from our AFURLConnectionOperation base
class.
[Issue #769] Resolving asymmetry in cached image case for UIImageView category
Updating OS X project settings
Merge pull request #768 from jparise/response-json-lock

Serialize calls to responseJSON using a lock.
Cleaning up formatting from pull request

Adding @dynamic for lock property
Merge branch 'master' of https://github.com/Fl0p/AFNetworking into Fl0p-master
[Issue #767] Consolidating macros
Wrapping AFHTTPBodyPart switch statement with #pragma to ignore -Wcovered-switch-default
Fixes warning: multiple methods named 'postNotificationName:object:' found [-Wstrict-selector-match]
Fixes warning: multiple methods named 'objectForKey:' found [-Wstrict-selector-match]
Fixes warning: weak receiver may be unpredictably set to nil [-Wreceiver-is-weak]

Signed-off-by: Mattt Thompson <m@mattt.me>
Compare NSURLRequest rather than NSURL

If you inadvertently load a nil URL in UIImageView+AFNetworking, the failure block of the image request operation is bypassed because [nil isEqual:nil] == NO. By comparing the URL request instead of the URL, the `isEqual:` test passes and the error is properly forwarded to the failure block parameter.
Limiting default Accept-Language header to 6 languages
Merge branch 'experimental-issue-737'

Conflicts:
	AFNetworking/AFHTTPClient.m
Adding lock around AFHTTPRequestOperation -responseString
Adding lock around AFURLConnectionOperation -responseStringEncoding

Adding check for self.response in AFURLConnectionOperation -responseStringEncoding
Merge pull request #772 from 0xced/fix-uiimageview-nil-url

Compare NSURLRequest rather than NSURL