Only encode JSON with UTF8, following recommendation of NSJSONSerialization documentation

Signed-off-by: Mattt Thompson <m@mattt.me>
Merge branch 'master' of github.com:AFNetworking/AFNetworking
Attempting to add the pinning mode as an example.
Fixed SSL Pinning
- SSL Pinning switch case was not being applied if a .cer file was found in the bundle.
- SSL Public Key pinning was broken because we didn't make a call to SecTrustEvaluate before SecTrustCopyPublicKey
Clean up
Using indexesOfObjectsPassingTest to calculate numberOfFinishedOperations in -enqueueBatchOfHTTPRequestOperations:

Signed-off-by: Mattt Thompson <m@mattt.me>
Adding __unused to block paramters
[Issue #888] Fixing property attribution build warning in AFHTTPClient body stream provider
Added guard around adding a NULL object to an array
Revert "Added guard around adding a NULL object to an array"

This reverts commit c8e420990efc80a1eba059f9c34fab0023efdcfc.
Merge pull request #900 from kcharwood/ssl_pin_example

Fix SSL Pinning