* Force root url if set by user
If user sets APP_URL, force the root url to that. Empty strings result in default behavior.
Fix some of the urls in the laravel templates.
* Docs update
* Add base_url
* Allow trusted proxy via APP_TRUSTED_PROXIES
Set to '*' by default to emulate legacy behavior.
Set up doc describing environment variables
* Create helper to parse environment variables into arrays properly.
* Update doc blocks