hdf5_ep

[svn-r5135] Purpose:
    Features.
Description:
    Error stack used to report only hdf5 predefined error messages
    because it takes only static strings.  Runtime defined messages
    were not pushed to the stack.
    Added the means and macros to push MPI error strings onto the
    hdf5 error stack.  Added a new minor error class as H5E_MPIERR
    for this class of messages.
    H5Epulbic.h, H5E.c:
	Added H5E_MPIERR and its minor class description.
    H5Eprivate.h:
	Added HMPI_XXX macros to push MPI error strings to the stack.
    H5FDmpio.c:
	Changed couple places to use the new macros to test the new
	macros.  A more through changes to make use of these new
	macros will be done later.
Platforms tested:
    eirene (serial, parallel)
    modi4(parallel)