add a facility to cache a pointer to symbol values that caches a pointer to the dereferenced value
add an object that can helps capture profiling information
cleanup display of an empty statistic
add a facility for dynamic values to be smarter about the need to recalculate based on whether input data has changed since the last evaluation
added statistics to determine how long each machine is spending in stable state processing and in message processing
fix bug where machines with only stable states were not being marked as active
initialise mq_interface correctly