Watch configuration files and reload them when they change
There are a few changes here; it might make sense to review them one by one. It includes some refactoring of how we handle configuration loading in the first place, to simplify and correct our path handling a little.
Please approach all these patches with skepticism: it's the first time I've written something like this.
Some questions to ask during review are:
- Is this feature secure?
- Should it indeed be off-by-default?
- Should we do this at all?
- What does this imply for #285 (closed) (configuration reworking)?
Closes #270 (closed)