Digging the UID and GID out of an os.FileInfo should work on all Unixy
systems, so move it from Linux-specific implementation file to a file
that we also build for Darwin.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
Detect files that are hard linked together, and use that information to
avoid copying their contents more often than we have to.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
Closes: #1789
Approved by: rhatdan