hdf5_ep

[svn-r20772] Problem:
Test scripts sometimes need to filter some system-specific messages from the
actual output so that it can match the correct expected output. These filtering
functions, ususally called "STDOUT_FILTER()" and "STDERR_FILTER()" were being
repeated in individual test scripts.  This becomes a maintenance problem and
is error prone.

Solution:
Extract the two filter functions code to bin/output_filter.sh and then each
test script sources it in. This allows reuse of coding and is much easier to
maintain and to add new filtering.

Tested:
LLNL Zeus (linux64 cluster) and Dawndev (Blue-Gene cluster), both for serial
mode only.