fix(avatars): disable remote URL option
fix(avatars): integrate profile server backend for profile images
Updating to express@3.17.1
fix(errors): use the correct context for error messages

Fixes #1660.

This issue occurred because the context of an error was being discarded as the error was rethrown in the form submission handler. Rather than depend on error context being passed around, we store it on individual error objects.
Merge pull request #1659 from pdehaan/issue-1658-express

chore(build): Updating to express@3.17.1
Pre-merge cleanup

* remove unused deps from base.js.
* remove `errors` parameter in `displayError` calls in views/mixins/service-mixin
Merge pull request #1584 from mozilla/profile-images-backend

fix(avatars): integrate the profile images backend

I give this my r+.
feat(metrics): Log `entrypoint` to the metrics.

* Add the FxDesktopRelier that imports `entrypoint` and `context` from the URL.
* Relier extended to import `service`, `redirectTo`, `client_id`, and `state`
* Initialize either the FxDesktopRelier or normal Relier on startup.
* Instead of Metrics importing values directly from the URL, they are fetched from the Relier and passed in on creation.

fixes #1568