Added support for automatic cleanup of objects that are run.

@jeffdh @mcellis33 

This is the beginning of the cleanup procedure.  I want to get this merged before we start removing things.

This makes the name of containers reflect the topology names.  This also enables multiple copies of a topology, although that's not the point yet.

You can test this with  `pickett --debug run -r /vagrant/mesa.src:/mesa mesa.test`.  When that runs to completion, there are _no_ containers left over in `docker ps`.