These two modules are a dependency of virt-v2v. Since we intend to
split virt-v2v from the other OCaml virt-* programs, we cannot have a
dependency between virt-v2v and virt-customize. Instead we must move
the modules to a common directory (common/mlcustomize) and have both
tools depending on the modules from there.
This is simple refactoring and should not affect how the programs work
or are tested.