add support for adding values to json arrays.
fix a fixed-size buffer issu in sendMessage()
fix an issue where the state of machines declared globally and used within a stable state test via a GLOBAL statement would not resolve.
add a persistent status command to be used by persisted to collect state of persistent objects. Not sure that this should remain as the update should be happening automatically on channel setup anyway.
initialise persisted by communication with iod/cw, not by reading the persistent database
added a test of the use of global machine state in stable state evaluations