All submodules (kernel, bootloader, redoxfs, userutils, installer, base)
use path = '../libredox', '../syscall', '../redox-scheme' to reference
sibling forks. When the cookbook copies these to recipes/core/<name>/source/,
Cargo resolves the relative paths from the copy location, not the symlink
target. Added symlinks at the recipe level so all resolutions go through
the same path: recipes/core/<name>/<dep> → local/sources/<dep>.
