This adds a `--no-pivot` cli flag to runc so that a container's rootfs
can be located ontop of ramdisk/tmpfs and not fail because you cannot
pivot root.
This should be a cli flag and not part of the spec because this is a
detail of the host/runtime environment and not an attribute of a
container.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Users of libcontainer other than runc may also require parsing and
converting specification configuration files.
Since runc cannot be imported, move the relevant functions and
definitions to a separate package, libcontainer/specconv.
Signed-off-by: Ido Yariv <ido@wizery.com>