Added new HStoreConf parameters to control whether the MarkovPathEstimator + MarkovEstimator are allowed to learn new states in the MarkovGraphs as the txns execute. The feature was always there (sort of), but it was just turned off by default. The MarkovEstimator will recognize when the path estimator failed to create a complete path to a terminal state and then instruct the PartitionExecutor to provide it with updates. We had this before but I guess it was broken and I never really had test cases for it. Ok it's time to eat dinner with KB downstairs...