Code review comment for lp:~eeejay/mago/dry_run

I am not that excited of the way I implemented this either. I think the dry run option (as opposed to test discovery) option is useful, because a user could have a fairly long command that includes many suites and specific cases, then she could run a "dry run" to see that the right things will be run before actually running the tests.

I am not married to the "dry run" concept or the code, I just need a test discovery mechanism so we could integrate well with checkbox.