Test with Facebook Graph API version 2+

[mnoorenberghe]

Make sure we handle:

• not having access to the username anymore
• having an app-specific user ID

[mnoorenberghe]

Some quick testing seemed so show that the common case works.

• Undefined property: stdClass::$email preventing account creation #13 can be a problem since the user can uncheck the email permission. I added a warning in 5ce1638 to help.
• Deal with Facebook friend list policy change #16 Pre-approval won't work as-is since the username and id field that Facebook returns are app-scoped.
  • The only workaround I know of would be to try and use the Requests dialog to send a message to the users and get an app-scoped ID in return. It's unfortunate that FB has made it necessary to send requests to users just to pre-approve them