Fix 'rno' auto increasing bug while add a new feature

1. if exists dir /release/1, seems execute 'minco deploy' again won't create /release/2. This will cause softlink node_module not work.


2. I encounter a scenario that my git repo contains more than one node project, I know this is not good, but for our startup team, I still want to get benefit of minco, so I add a feature to deploy.json called 'prj_git_relative_dir', by making this minco can only copy specified dir to release dir instead of whole git repo.