This handles the transient store options from the container/storage
configuration in the runtime/engine.
Changes are:
* Print transient store status in `podman info`
* Print transient store status in runtime debug output
* Add --transient-store argument to override config option
* Propagate config state to conmon cleanup args so the callback podman
gets the same config.
Note: This doesn't really change any behaviour yet (other than the changes
in containers/storage).
Signed-off-by: Alexander Larsson <alexl@redhat.com>