revert a part of r31835 and set 'cell' same as 'here' if 'cell' is undefined, so that we can use the same formbox for both ListBox and non-ListBox using 'cell' parameter.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@36894 20353a03-c40f-0410-a6d1-a30d3c3de9de