Allows users to log in to WordPress using Google+ or Facebook.
Adds a configuration panel under Settings where users can set API keys.
Upon successful login, depending on the service, users will be redirected to either:
— www.mywebsite.com/facebookcallback/
— www.mywebsite.com/googlecallback/
Both links have a common CSS class: “gp_sociallogin”.
Google’s login link has a specific class: “google”.
Facebook’s login link has a specific class: “facebook”.