--safe-mode / --dry-run Option

[code-poel]

It's currently really easy to accidentally delete an entire directory tree simply by forgetting a /* in your modman config. It would be really nice to have a --safe-mode or --dry-run option that we could use that would dry run the install just so we could catch this stuff before wiping out core directories while we're hammering out configuration file for a new module.

Possible feature request?

[aepod]

Ticket for request: #38

This seems like it really would be a nice feature.