closes #268 Split stress test into 3 Map reduce jobs.  fixes #272 fixes ...

...#225
Should this be hard coded to 8?  Print could accept a nodeSize argument.  Another option is to not include nodeSize in root row.  While it's needed for all children, it's not necessary for the root row.  The row id of root node could be `00:root` but this would require some rework of Node class.