To avoid confusion about what to return on a Spring MVC endpoint, change toResources to not return `List<D>`, but instead `Resources<D>`. This clearly ensures when used to construct Spring MVC endpoints, will return a type Spring HATEOAS will properly marshal.
To support people that have already built apps on top of Lists, include a `toList<D>` method that honors the old contract.
Related issues: #493
Related pull requests: #572
a597960711