Initial mockup of a strawman version 2 API

[buske]

This pull request is not intended to be merged and rather provides a place to discuss a concrete but simple example for the way the next iteration of the API might look.

Feedback would be greatly appreciated.

The overview provides an outline of the design and structure of the request and response. There are two other files with some simple use cases, but I'll try to add more examples to this pull request later (if anyone else wants to contribute, please do!).