hdf5_ep

[svn-r5014] Purpose:
    fetures
Description:
    The example code used to just run parallel I/O test in the current
    directory which is most likely where the program is compiled.
    In general, this directory is most likely not a parallel file system.
    Therefore, the example code often fails.
Solution:
    Add an option "-f <prefix>" for specifying the correct test files
    pathname prefix.  The program now requires an explicite file prefix
    either via the "-f" option or the environment variable $HDF5_PARAPREFIX.
    (With the proper setup of $HDF5_PARAPREFIX, the example code can run
    automatically in situtaions such as batch job or gmake check.)

    Also added feature to cleaup up the test files created.
    Of course, an added option "-c" to turn OFF the cleanup action.
Platforms tested:
    eirene, modi4, dangermouse (all parallel modes).
    modi4 (serial) just to verify it can compile.