Make login modal work and add more robust autofill handling.

* Fix bug in "$auth.logIn" method where promise rejection wasn't being
  returned.

* Make login modal functional.

* The "autofill" directive now sets an interval timer to refresh the
  backing model variable with the input.  This is done so that broswer
  autofills will get pushed to model.

* Add "autofill" directive to all inputs that the browser might touch.