minor
renaming directives to plans and machines to systems, also reorganizing code
enough simple bugfixes to make test_simple_system test pass
enough simple bugfixes to make test_simple_system test pass
enough minor fixes that the test_complex_system test now run successfully
minor bugfixes to get run selector test to run successfully
removed completed items from todo
updated README with renaming
cleaning up last vestiges of the terms machine and directive
commented out debugging statements