Let's move off our custom QuaZip. In the olden times we needed the
custom version of QuaZip, as it was basically unmaintained and on
SourceForge (eww). But nowadays it's maintained and on GitHub. See
new GitHub page: https://github.com/stachenov/quazip
* It is added as a new submodule: https://github.com/MultiMC/quazip/tree/multimc-1
* Its build system has been entirely replaced to remove the existing issues with it
* It now has working unit tests
* No more patches needed
* It has a static linking exception in its license now, but we use it shared anyway
