Add Facebook login function and Claw data

/**/ That is the Facebook global data we could get for each logged in
user.
FB.__globalCallbacks.f272f3fff4({
    "id": "725070774242510",
    "email": "zexianzeng\u0040gmail.com",
    "first_name": "Zexian",
    "gender": "male",
    "last_name": "Zeng",
    "link":
"https:\/\/www.facebook.com\/app_scoped_user_id\/725070774242510\/",
    "locale": "en_US",
    "name": "Zexian Zeng",
    "timezone": -5,
    "updated_time": "2014-09-28T15:44:42+0000",
    "verified": true
});