hdf5_ep

[svn-r5058] Purpose:
    Feature/bug fix
Description:
    The 'snapshot diff' command is run in all cases, even after the initial
    "snapshot diff" and hosts are polled to run the test.  It would not cause
    any harm except wasting time repeating diff'ing.  Also, the path is
    quite right to invoke snapshot by merely "bin/snapshot diff" since it
    has not "cd" to the right directory yet.
Solution:
    Added a new option of "-nodiff" to skip the special diff request.
    Then make "runtest" to call itself again with it to prevent
    any further unnecessary diff'ing.
Platforms tested:
    eirene