get_fun needed change to cope with "('a fset) fset" types...this needs composition (op o); now id_simps contains also id_o and o_id, and map_id is also added in QuotList.thy; regularize and cleaning needed to be hacked (indicated by "HACK")...THIS NEEDS ATTENTION!!!; except two lemmas in IntEx, all examples go through; added considerable material to FSet3; tuned FIXME-TODO