Revert "Remove obsolete classes"

This reverts commit 127fcf2f7076a0d44301bdcfe83e233d134ef951.

Compile fails otherwise...
Revert on DI part 1: remove two unused classes

I do DI wrong, so I might as well not do it until I know how to do it right.

Start by removing two "front-facing" classes which were unused anyway.