vchoi_fork

[svn-r19831] 
Checked in fix for failure in shape same tests that appeared after
Quincy's recent massage of the test code.  The problem was a race
condition created when Quincey re-worked the code selecting either
collective or independant I/O.

Previously, when independant I/O was selected in the test, I had
used H5Pset_dxpl_mpio() and H5Pset_dxpl_mpio_collective_opt() to
select collective semantics with independant I/O going on under
the hood.  Quincey modified this to call H5Pset_dxpl_mpio() when
collective I/O was selected, and do nothing in the independant I/O
case.  As a result, processes were able to race ahead and
modify the initial values of the data set before some processes
had verified that the initialization was correct.

Solved the problem by adding barriers, and making all barriers
dependant on independant I/O being selected.

Tested parallel on amani and phoenix.  h5committested.