More flexible rake tasks

Hi,

I thought the rake task was not flexible enough when running specs in a certain directory or, more importantly, fetching stats. What I sometimes have is a dedicated directory for a part of my application, e.g. 'api' or 'mobile', which then holds the usual subdirectory structure of rspec. Running `rake stats` would ignore those dirs and I would like them to being included automatically. So I thought making the tasks adapt to it would be a nice addition.