AFImageCache protocol should inherit from NSObject
fix for import as cocoa touch framework as module to a swift only project

Signed-off-by: Stephan Krusche <krusche@in.tum.de>
Fixes an issue with the request serializer silently handling an error

When a query string serialization block is set on
`AFHTTPRequestSerializer`, if it was to fail with an error it would be
silently handled and the serialization would still return an NSURLRequest.
NSSecureCoding

Fix minor typo in which NSecureCoding was referenced in comments and pragmas, and I assume NSSecureCoding was intended.
[Request Serialization] Add `valueForHTTPHeaderField:`

Since we have `setValue:forHTTPHeaderField:` it makes sense to have a
similar method to retrieve them.
Merge pull request #2230 from robertmryan/master

NSSecureCoding
Adding test for success block on 204 response
[Issue #2201] Adding @synthesize delegate to AFMultipartBodyStream
Merge branch 'master' of github.com:AFNetworking/AFNetworking
[Issue #2237] Correcting documentation for URLSessionDidFinishEventsForBackgroundURLSession delegate method and reorganizing code accordingly
Merge pull request #2232 from kylef/request-serializer-valueForHTTPHeaderField

[Request Serialization] Add `valueForHTTPHeaderField:`
Minor reformatting
Merge branch 'AFURLRequestSerialization-error' of github.com:kylef/AFNetworking into kylef-AFURLRequestSerialization-error

Conflicts:
	Tests/Tests/AFHTTPRequestSerializationTests.m
Fixing 204 response test
Merge pull request #2206 from krusche/master

fix for import as cocoa touch framework as module to a swift only project
Merge pull request #2179 from marcelofabri/patch-1

AFImageCache protocol should inherit from NSObject
[Issue #2239] Adding [manager.reachabilityManager startMonitoring] to README
Merge branch 'master' of github.com:AFNetworking/AFNetworking
Fixing merge from 61b7a9babab736fc05fc11fb2d2b57e58be982c9
[Issue #2156] Fixing issue caused by passing nil as destination in download task method