suzerain: warn on NaN grdelta

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@42267 0bd85f0b-c151-43b9-a1e9-27231104551f
suzerain: add new options to OPTS

Unusable until now.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@42268 0bd85f0b-c151-43b9-a1e9-27231104551f
suzerain: show rms.fluct only if Nx, Nz > 1

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@42269 0bd85f0b-c151-43b9-a1e9-27231104551f