TODO.txt

Loose TODO:

- allow to always show certain fields for selected types even if unchanged in order to see relevant context
- replace many of the manual type classes with shapeless automatic type class derivation https://github.com/milessabin/shapeless/blob/master/core/src/main/scala/shapeless/typeclass.scala
- introduce intermediate representation to allow alternative String renderings and allow easy testability of added/removed
- split Show and Diff