setters for some properties of the form should be called by edit().

This is usefull, for example, when property A acquires its default value from
property B, and both are editable in the same form. We don't want A to be set
to B's old value when the user changes B's value and A had no value set.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@19605 20353a03-c40f-0410-a6d1-a30d3c3de9de