Merge pull request #972 from carueda/platform_agent_R2C4

add recursion argument to various platform agent commands
- add recursion parameter (default True) also to PAUSE, RESUME, and CLEAR.
- include CLEAR command in test_some_state_transitions
- prepare the various utility test methods with the recursion parameter (NOTE that *no* tests are yet enabled with recursion==False)
merge upstream/master