hdf5_ep

[svn-r5516] Purpose:
    Tidy up
Description:
    Old version showed tons of output even if MPI_Offset is too small
    to support multiple GB sized files and destined to fail.
    Output is pretty confusing.
Solution:
    Prints the signness and size of MPI_Offset for information.
    Skipped tests if MPI_Offset is not big enough to support the file
    sizes.
Platforms tested:
    modi4, eirene, burrwhite (all parallel).