Add "unshare", "create-storage-layer", and "storage-layers" commands to
the test helper, along with a "-U" flag to have it unshare when handling
a given command.
Add "-o" as an alias for the "--owner" flag to "copy".
Add "-r" as an alias for the "--ro" flag to "mount".
Add a "-q" flag to "layers" so that we can list just the IDs.
Drop mention of a couple of not-implemented options from
docs/containers-storage-create-layer.md.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
Nalin Dahyabhai