Logrus_auth authentication

[eluser]Patrick Spence[/eluser]
Using Phil Sturgeons great oauth2 library (https://github.com/philsturgeon/codeigniter-oauth2) I have this working to log in via facebook, gmail or windows live if anyone is interested.

I want to add a toggle so that it only offers that option if you tell it to in the config, so there is some cleanup for that as well as making the option to force a email authentication for legacy accounts if needed..