use robots.txt-style 'Name: value' formatting

[jmason]

I think this is a fantastic approach and well worth doing. One thing that would improve it IMO would be to use a "Header: value" style more similar to robots.txt, though;

So for instance, instead of

[upstream]
krystal.co.uk

it'd use something like

[upstream]
Domain: krystal.co.uk

Or other kinds of identifier:

[upstream]
Name: Ecotricity Group Ltd

This gives more room for extensibility in future, where new forms of addressing or relationships can be supported.

[derhuerst]

I propose to use format like TOML, as it is both highly human-readable and can be parsed in a strict manner.

[mrchrisadams]

We ended up using TOML in the end, so I'm closing this for now.