UC-53 Create a new module for Facebook v2+

Update the Facebook PHP and JS SDK's to the new version and create a new extension to implement the FB connect functionality through them.

https://wikia-inc.atlassian.net/browse/UC-53
Couple minor errors. Should probably read: 'You can also <a id="fbConnectDisconnect" href="#"> disconnect your Wikia account from Facebook.</a> You will able to continue using your Wikia account as normal with your history (edits, points, achievements) intact.'