New to 1.14, Mojang stores .mca files which don't contain chunks in the
poi folder.
Note: we explicitly filter *out* the poi folder, instead of filtering
*to* the regions folder, since old versions of minecraft had regions
directly in the world folder (instead of a regions subfolder).
This converts the project into a multi-module Gradle build.
By default, Git does not show history past a rename, so use git log
--follow to see further history.
