Removed the DependencyTracker handle out of ExecutionState and put it into the LocalTransaction handle. We will probably be able to get rid of ExecutionState entirely now #125
Working on test case for adding prefetching results in the DependencyTracker before/after they are needed by txns. Removed the 'predict_singlePartitioned' input parameter to BatchPlanner.plan(). I forget why we had it in the first place. #125