This update is a big refactor with stability around animation ending, took out some hacky things, some optimization but not a lot, and extra debugging and testing.
We now enforce animation-fill-mode: forwards on animations, and the Animation.onfinish callback to prevent flashing and bad timeouts. Unfortunately, the best way to perform CSS class animations is still setTimeout, but repeat renders (setting state when unnecessary) is prevented.
Breaking changes:
Renamed the <Smoothr> configAnimationSetDuration to beforeAnimation.
Renamed the <Route> pathMask property to pathResolve.