safer default values for polydispersion and lognormal fix
safer default values for polydispersion and lognormal fix

lewisodriscoll/sasview,SasView/sasview,SasView/sasview,lewisodriscoll/sasview,SasView/sasview,lewisodriscoll/sasview,lewisodriscoll/sasview,SasView/sasview,SasView/sasview,SasView/sasview,lewisodriscoll/sasview