Fix for broken salt cmd return codes - issue #7013

- new test related states that can be used to provide success / failure on request.
- fixed the broken logic chain that handles return codes
both when the minion decides what retcode to propagate to the master
and when the master decides what return code to return to the invoked salt cmd
- added new log.debug and log.trace statements to assist with further work on ensuring return
codes are properly handled by all components of salt.