Simplify setting up of the urls, and allow the host url to be set via the PUBLIC_URL environment variable to be compatible with awsbox
Improve the config interfaces so that config does setupUrls automatically, and tidy some of the config get/sets in server.js
Fix documentation and lint failures
Merge pull request #217 from Standard8/url_host_to_env

Simplify setting of the URLs for hosts, allowing PUBLIC_URL environment variable so that it can be set from awsbox