Introduced SuiteRunner to simplify RunCommand

RunCommand is not under specification and had some Runner logic in it. This delegates that control loop into a SuiteRunner collaborator and shortens RunCommand.

We discussed the potential for multiple suites, I'd like to do that as a separate change but if there is a simple way to add it here please comment. One way would be some sort of SuiteAggregate that the locator could return?