suzerain: add comments to summary

I'd failed to include the comment strings in the resulting
HDF5 summary file.  Thanks to Nick for noticing the
omission.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@45302 0bd85f0b-c151-43b9-a1e9-27231104551f