This is necessary to enable creation of common qemu-img options which will
be specified before command.

The patch also enables '-V' alias to '--version' (exactly like in other
block utilities) and documents this change.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 1466174654-30130-7-git-send-email-den@openvz.org
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>