Slight `makerpo` refactor

Hi,

I've re-factored `makerpo` a little. This pull-request does change the `makerpro` invocation slightly but does so that a a new "automatic" featured could be added.

The usage changes very slightly. Instead of:

    ./makerpo --list

You would use;

    ./makerpo -t list

The `-t` is the task flag. So you would now use `./makerpo -t build` or `./makerpo -t b` to start a build. This allows a new flag to be added `-a`. The `-a` flag enables automatic mode so that the entire package tree can be built without manual intervention.

I have a big pull-request that I am queuing up for tomorrow, and sadly, this pull-request will require merging in order for my next pull-request to apply cleanly. Sorry about that, this should be the last time my pull-requests are chained in such a fashion.

Regards, Martin.