Add support for new Firebase 3.x.x. authentication methods

There are a bunch of new authentication methods in the Firebase 3.x.x SDK which are not found in AngularFire 2.x.x. These include the following:

• firebase.auth.Auth
  • applyActionCode()
  • checkActionCode()
  • confirmPasswordReset()
  • fetchProvidersForEmail()
  • getRedirectResult()
  • verifyPasswordReset()
• firebase.User
  • getToken()
  • link()
  • linkWithPopup()
  • linkWithRedirect()
  • reauthenticate()
  • reload()
  • sendEmailVerification()
  • unlink()
  • updatedProfile()

The only reason we include the existing set of authentication methods is because those are the ones that were around in the Firebase 2.x.x SDK. Now that we have a bunch of new methods, we should probably include them in the $firebaseAuth service or else users will have to drop down to the vanilla Firebase SDK half of the time.

The counterpoint to adding them is that we end up just re-implementing a bunch of existing functionality in the vanilla SDK. Is there a different approach we can take to handle the $digest loop issues that doesn’t involve use wrapping every method in the underlying SDK?

cc/ @katowulf, @abehaskins, @davideast - Thoughts?

[davideast]

Is there a different approach we can take to handle the $digest loop issues that doesn’t involve use wrapping every method in the underlying SDK?

Unfortunately not, any async event will need to be wrapped.

I think it’s important to provide these methods to keep continuity for the developer, so I’m on board 💯.

[jwngr]

We should also consider deprecating $getAuth() in favor of $getCurrentUser().