Adds SSLPinningMode to AFURLConnectionOperation and defaultSSLPinMode to AFHTTPClient.
Fixes memory leak.
Gets rid of for loop to check if public key is present.
Added in a property to handle invalid SSL certs
Stashing merge
Replacing #ifdef macro check for Security to _AFNETWORKING_PIN_SSL_CERTIFICATES_
Removing #warning about Security framework
Fixing compiler warnings in SSL pinning initializers

Minor refactoring
Adding Security framework to example projects and adding #define for _AFNETWORKING_PIN_SSL_CERTIFICATES_
Adding documentation about SSL Pinning
Minor reformatting of AFHTTPClient constants documentation
Adding Security frameworks to podspec, and defining _AFNETWORKING_PIN_SSL_CERTIFICATES_
Fix documentation for appendPartWithFileURL:name:error:.

The documentation said that the values for filename and the
Content-Type header was being obtained from a NSURLResponse,
but since this is a request, no response is available yet.

The documentation has been changed to reflect better where
those values really come from.
Add method to allow custom file name and content type for multiparts.

The previous method was selecting the file name and the MIME type
automatically depending on the given file URL.

The new method allows specifying a custom file name and a custom
MIME type for the those parts.
Adding comma (,) as a percent escaped character since it's in the reserved words per the RFC
Reimplement AFMultipartBodyStream as AFMultipartBodyStreamProvider vending one side of a bound CFStream pair, to avoid subclassing NSInputStream and fix #781
Delete useless commented-out call to handleOutputStreamSpaceAvailable, and fix the stream:handleEvent: bit flag check
Fix deadlock from trying to do a dispatch_sync on the main queue when already on the main thread
Fixes -[AFURLConnectionOperation totalBytesRead] threading issue.
Merge pull request #825 from OliverLetterer/thread-issue

Fixes -[AFURLConnectionOperation totalBytesRead] threading issue.