add support for userInfo in notifyLogin request

[lsmith77]

see also http://developers.gigya.com/020_Client_API/020_Methods/socialize.notifyLogin

userInfo (JSON object/string)

This parameter allows you to provide Gigya with a site's user profile data. This ensures consistent user experience. Gigya uses this information, for example, in plugins that show user info, such as the Chat and the Comments plugins. 
The object may include the following fields: nickname, photoURL, thumbnailURL, firstName, lastName, gender, age, email.
For example:
userInfo: { firstName: "David", gender: "m", age:30 }

However from looking at the relevant buzz method the relevant information is currently not passed along:
https://github.com/opensky/GigyaBundle/blob/master/Socializer/Buzz/MessageFactory.php#L128

So it will require some changes to the calling API's too.