* Do not re=download release files.
* Efficiently handle dependencies: do not try to download \*.deb files when they already downloaded, do not try to extract them more than one time.
Can be set to the path to packages/ directories in other repos (like
unstable-package/packages/, termux-root-packages/packages/,
..). buildorder.py then searches these directories for packages and
dependencies
Use scripts/buildorder.py with a new -i flag to get all dependencies
(including subpackages). The script now also spits out both package
name and package dir, to make it easier to build packages from another
repo.