Use newrat as default mode-finder

Tends to perform better than csminwel

doc/manual/source/the-model-file.rst

@@ -6699,7 +6699,7 @@ observed variables.
                 takes the return value of that function as the
                 posterior mode.
-       |br| Default value is ``4``.
+       |br| Default value is ``5``.
     .. option:: additional_optimizer_steps = [INTEGER]
                 additional_optimizer_steps = [INTEGER1:INTEGER2]

matlab/default_option_values.m

@@ -444,7 +444,7 @@ options_.silent_optimizer = false;
 options_.prior_restrictions.status = 0;
 options_.prior_restrictions.routine = [];
 
-options_.mode_compute = 4;
+options_.mode_compute = 5;
 options_.additional_optimizer_steps= [];
 options_.mode_file = '';
 options_.moments_varendo = false;