vchoi_fork

[svn-r19959] Bug: the VRFY macro, for some reason, called MPI_Finalize() when it encountered
error and wanted to exit the test program. This was not good since if only a
subset of processes called MPI_Finalize(), the other processes will likely
hang.  That happened in AIX that it would waited till the alarm signal to kill
the processes. Definitely a waste of time.
Solution: Changed it to call MPI_Abort.

That showed another problem. HDF5 has setup atexit post-process to try to close
unclose objects, release resources, etc.  But if the MPI processes have
encountered an error and has been aborted, it is not likely any more MPI calls
can function properly. E.g., it would attempt to free some communicators in
the HDF5 MPIO file handle. It would again hang.
Solution: need to call H5dont_atexit() to disable any atexit post-processing.
This must be done early, like before calling H5open. This is added to each
parallel test main program.

testphdf5.h:
    Changed macros VRFY and MESG. Added comments too.

testphdf5.c:
t_mpi.c:
t_cache.c:
t_shapesame.c:
    Added H5dont_atexit.

Tested: h5committest.