Two important differences:
1. The app only looks in one file for settings: config/application.yml. If you want to override something, do it in that file. It is gitignore'd. If config/application.yml does not exist, or exists but is in the old format, you'll get a nice friendly set of instructions on how to convert your old file.
2. script/server settings are no longer in application.yml. They have their own settings file - copy config/script_server_config.yml.example to config/script_server_config.yml. This is also gitignore'd. script/server will print a message and exit if that file doesn't exist.
