Rewrite SAUCE without that much hackery

[moschlar]

This project has already reached the point where it is so full of various hackeries that it is a huge burden to fix stuff and to keep its dependencies up-to-date.
I suggest it being rewritten from scratch on a clean slate.

I think most of the bad technical debt exists in the management layer (Event, Lesson, Team, User, ... - e.g. the Crud Rest Controller stuff (CRC) and the templates).
The runner functionality and parts of the model can probably be re-used.