suzerain: superclass of argument

Making this easier to use without an operator_base instance.
Caller still needs to provide some wall-normal locations,
but that requirement is pushed out of the method.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@45114 0bd85f0b-c151-43b9-a1e9-27231104551f
suzerain: permit eps slop in min/max values

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@45115 0bd85f0b-c151-43b9-a1e9-27231104551f