In the API:
`Writable` changed to `ReadOnly`
`Populate` changed to `NoCopy`
Corresponding CLI options updated to:
`volume-writable` changed to `volume-readonly`
`volume-populate` changed to `volume-nocopy`
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
(cherry picked from commit 56f3422468a0b43da7bae7a01762ce4f0a92d9ff)
Signed-off-by: Tibor Vass <tibor@docker.com>