This allows non-recursive bind-mount, i.e. mount(2) with "bind" rather than "rbind".
Swarm-mode will be supported in a separate PR because of mutual vendoring.
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
This moves the platform specific stuff in a separate package and keeps
the `volume` package and the defined interfaces light to import.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>