Polling of currently authenticated providers

[mattstrick]

Goals

1. Create an easy way to tell which providers are currently authenticated

Non-Goals

Background

I am working on an app that requires multiple Providers be authenticated at once, but according to the documentation I can only tell if a user authenticated with a Provider on SignIn. I can only tell a user has signed out of a Provider if they use the SignOut function, I can't tell if a Provider has timed out since the session doesn't say which Providers are currently signed in.

Proposal

Please expose the currently list of authenticated Providers to be returned when I call the auth() function. I don't currently have the bandwidth to help with this.