Turns on/off several heuristics that are used to determine if
nonlinear solution will probably not converge in a reasonable number
of steps. These heuristics are a sufficient reduction condition
(i.e. after 10 steps the residual reduces by at least 0.5% on each
subsequent step) and a cap on the growth in the residual (i.e. the
residual does not grow more than a factor of 
between any
two steps).
Regardless of whether or not these tests are turned on, the residual is checked for obvious non-convergence indicators (i.e. IEEE NaN and infinity) on hardware that supports it.