SYNOPSIS
$0 [--repo /my/repo ] [--link /my/link] [--version release-x.x.x]
[--path /my/path ( default $repo/data ) ]
[--keep 10 (default 10)]
Version 'release-x.x.x' and 'rollback:release-x.x.x' are the same
Version backup refers to the $link.backup
Version backup\d* refers to the $link.backup\d*