[hrplus] pulled from Neelesh, tree changes and tree tests
[hrplus] bugfix in addRootMapTableEntry
[hrplus] added numRoots, getNodes tests, fixed the broken ContainerNode tests
[hrplus] added documentation
[hrplus] synced changes with Neelesh
[hrplus] cleaned Tree of RevTree constructor, still lost on version ids
[hrplus] added default constructor to HRPlusTree
[hrplus] more partition tests, more partition documentation