SAMKeychain Versions Save

Improve Swift compatibility. Thanks @kenmaz!

Built with Xcode 8.0 (8A218a)

Fix crash when SAMKeychainQuery is subclassed by @radex

Rename to SAMKeychain to avoid naming conflict in iOS 10.

• watchOS support
• tvOS support
• Fix keychain item accessibility (@lufthansa747)
• Annotate types with Objective-C generics
• Don't require module support (so it can be used from Objective-C++)
• Support access groups on OS X (@gabriel)

Carthage binary built with Xcode 7.2.1 (7C1002).

• App extension safe API
• Clean up warnings