Initial example for formally describing outputs from a Command

One possible way to add in additional information about results. This reuses the ``Parameter`` class and essentially has subclasses of ``Command`` define ``InParameters`` and ``OutParameters``. This is not fully worked out, but wanted to get at least one idea down for discussion. The ``MakeCommand`` command works from the command line right now (but the template it dumps is still pyqi v0.2 style.