hdf5_ep

[svn-r10593] Purpose:
Bug fix.

Description:
Data file name is hardcoded to be in current directory which does not
necessarily support MPIO. Changed it to /tmp/sds.h5 for slightly larger
chance of success but the eventual solution is to set it according to
environment variables.  Patch it this way for now.

Platforms tested:
mir.

Misc. update: