Start work on OAuth 2.0 support with Facebook Single Sign-On
Refactoring

Starting work to get the code in a well organized and usable order.
Want to use a static OAuth2 class for the login process.
Use a proper service-specific class to interact with the third-party
API.
Expanding Login Code
Ask Permission

Code successfully asks for permission seeking authorization.
Utilizing static class variables to hold OAuth App Secret, Client ID,
and login URLs.
Start Setup Instructions

and add disclaimer on making app secret public
OAuth2.0 Login is Working

file_get_contents wrecks app usability on HTTP 400 error. My
httpWorker::request can react to such problems.
Hopefully you just need to setup your own keys.php and direct users to
/login.php?service=fb
Update README