Update SDK

Kinvey update 1.27
Update to valid source
App delegate update

Set placeholders for sample in AppDelegate.m for Kinvey and FB
Update Facebook SDK to 3.8.0

Support x64 architecture (iPhone 5s and later)
AppDelegate Kinvey App Key and Secret for sample
Updated assets, ReadMe

Creating new Update - looks pretty in iOS 7,8
Warning fixes and clear credentials on logout

Fixed warnings
Clear credentials on logout
Update FBSDK to 3.20
Something strange with git

FBSettings in prev commit was MIDIFIED, now it is NEW file
Smaller image size optimisation, readme image fix
updated Facebook and Kinvey SDKs, optimized image sizes, updated README, screenshots and assets, closes #3