[bug 972919] Cleaned up app.js

A simple refactor. See the diff for details
[bug 972919] Removed CORS logic

In the previous Login strategy, other app's views would query the Login
server directly. This required the Login server to use custom middleware to
check CORS headers sent along with each request. Since each server now
communicates with Login on behalf of their views (using webmaker-auth &
webmaker-auth-client) the CORS logic is no longer needed.
[bug 972919] Removed outdated information from the readme

The change of strategy with the login server invalidated most of
the integration steps that were listed in the README. It still
needs an update (https://bugzilla.mozilla.org/show_bug.cgi?id=939845)
but that is outside the scope of this bug.
1.0.37
Fix bug 936507 - Remove deprecated create user route
Bug 972919 - Remove deprecated sso-ux.js
Bug 972919 - Remove deprecated console.js
Bug 972919 - Remove deprecated ui.js
Bug 972919 - Remove deprecated new user form
Bug 972919 - Remove AUDIENCE variable
Bug 972919 - Remove leftover CORS bits
Bug 972919 - Correct a fact
Bug 972919 - Remove an unused require()
Bug 972919 - Remove unused var declaration
Bug 972919 - Remove unused schema.js
Bug 972919 - Remove unused lib/extensions/*.js
Bug 972919 - Remove admin delete user route
1.0.38
Bug 1008247 - Update to webmaker-auth-client v0.1.0
Bug 1010375 - Update to newrelic v1.5.5