deal with login from email (bug 1095504, bug 1094498)

This copes with preverified login from zimbra and preverified login on device.

The one piece I haven't figured out is triggering the login events after handling the auth code via web activity; I get "Reload on login aborted by current view". Suggestions on fixing this?
`window.opener.location.origin` probably doesn't work on 1.1. We are [polyfilling `window.location.origin`](https://github.com/mozilla/marketplace-core-modules/blob/b48ea00f10607a89b36d1dc9f73d0b7b16ea901f/polyfill.js) but we'll probably need to manually assemble `window.opener.location.origin`.