Files that are suffixed with `_linux.go` or `_windows.go` are
already only built on Linux / Windows, so these build-tags
were redundant.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This changes the long-standing bug of copy operations not preserving the
UID/GID information after the files arrive to the container.
Signed-off-by: Erik Hollensbe <github@hollensbe.org>