Some parts of pkg/archive is called on both client/daemon code. To get
it compiling on Windows, these funcs are extracted into files with
build tags.
Signed-off-by: Ahmet Alp Balkan <ahmetb@microsoft.com>
Now that the archive package does not depend on any docker-specific
packages, only those in pkg and vendor, it can be safely moved into pkg.
Signed-off-by: Rafe Colton <rafael.colton@gmail.com>