Flip the default typispreferred setting from true to false. This affects

Flip the default typispreferred setting from true to false.  This affects
only type categories in which the previous coding made *every* type
preferred; so there is no change in effective behavior, because the function
resolution rules only do something different when faced with a choice
between preferred and non-preferred types in the same category.  It just
seems safer and less surprising to have CREATE TYPE default to non-preferred
status ...