miniblog.

I've been playing with https://github.com/orium/rpds as a replacement for im in difftastic, and it's a significant speedup! I saw a 30% runtime reduction in one case. im is great but sadly seems unmaintained. I suspect its 'small vector as a vec' design doesn't suit my use case.

The fun thing about maintaining crufty code is that you end up making a net reduction in code, even as you add small features.