suzerain: fix sharex arg

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@45622 0bd85f0b-c151-43b9-a1e9-27231104551f
suzerain: make reacting_summary.py backwards compatible with older sample data

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@45656 0bd85f0b-c151-43b9-a1e9-27231104551f