vchoi_fork

[svn-r9893] Purpose:
Temporary daily tests fix.

Description:
The newly added ph5diff is not quite compatible with the h5repack tool.
Disabled the ph5diff build (reverted back to building serial h5diff)
to allow daily tests to work while ph5diff is fixed.

Platforms tested:
Tested in heping both serial and parallel modes.

Misc. update: