UC-99 Manually confirm fb users who don't have email addresses with fb

When a user connects via Facebook but doesn't have an email registered with Facebook (eg, if they registered using a phone number), we have them enter an email address for us to use. We want to have user's confirm those email addresses. If they come from Facebook, then we'll still auto-confirm them.

Ticket: https://wikia-inc.atlassian.net/browse/UC-99
Most of the noise in this file is me pulling the anonymous function that was being passed as a callback to ```window.FB.login``` into the named function loginCallback below.

The other addition was adding [this case](https://github.com/Wikia/app/blob/UC-99/extensions/wikia/UserLogin/js/UserLoginFacebook.wikiamobile.js#L58-L66) for an unconfirmed user.