Migration utility

We need an automatic way to migrate from the old updater to the new. We need to preserve all the existing packages, but we also want to list as little dependencies of the „desired“ packages as possible. This is a problem, since openWRT's opkg does not store the information if a package was installed on user's request or as a dependency.

Subtask #129 (closed) (Basics of migrator)
Subtask #130 (closed) (Eliminate non-headers)
Subtask #131 (closed) (Integration)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information