hdf5_der

[svn-r25078] Test program that accepts parameters to control size of Datasets and Maps in container
and times/reports writes / persists / evicts / prefetches / reads.
Reads are of form "rank reads data it wrote", "rank reads data written by next rank" and "rank reads all data"
Reads are done from logged data, prefetched data, or data on DAOS.

Designed to give insights comparing performance of Arrays & KVs
and accessing data in various layers of the storage stack.