Use the "has-error" CSS class for simple_form fields that have some error.

This actually displays errored fields in red. We were using the "error" CSS class which is not correct for Bootstrap 3.
Edit Registration view now uses its own layout.

We need a layout almost equal to the application layout, but with the same angularJS controller as the devise layout and displaying the devise alerts div; otherwise things like displaying devise alerts and hiding the Add Subscription button do not work in the Edit Registration view.