It is statically initialized to the real back-end OPAL show_help
function. During orte_show_help_init(), the variable is re-assigned
with the value of the back-end ORTE show_help function (the one that
does error message aggregation).
Therefore, anything that calls opal_show_help() after a certain point
in orte_init() will have their show_help messages be aggregated.
w00t! Even code down in OPAL -- that has no knowledge of ORTE -- will
have their messages aggregated. '''Double w00t!'''
During orte_show_help_finalize(), we restore the original pointer
value so that it something calls opal_show_help() after
orte_finalize(), it'll still work properly (but it won't be
aggregated).
This commit was SVN r24185.