Arvados

This would make life easier for anyone going through any kind of install.

• Section ordering should be consistent. (I think I personally vote for production, then development, but consistency is the most important thing. We've gotten good enough about making tests self-contained I don't think we ever need to define that or the common section.)
• Placeholder values should follow consistent style. e.g., URLs should use uuid_prefix.example.com as appropriate.