Add colander magic for association proxy fields

hopefully now any association proxy fields which are included, will be given
the appropriate type and widget.  however this still doesn't work for the
readonly rendering of fields...

tailbone/views/departments.py

@@ -64,14 +64,8 @@ class DepartmentsView(MasterView):
         super(DepartmentsView, self).configure_form(f)
         f.remove_field('subdepartments')
         f.remove_field('employees')
-
-        # TODO: widget should not be necessary, per type
         f.set_type('product', 'boolean')
-        f.set_widget('product', dfwidget.CheckboxWidget())
-
-        # TODO: widget should not be necessary, per type
         f.set_type('personnel', 'boolean')
-        f.set_widget('personnel', dfwidget.CheckboxWidget())
 
     def template_kwargs_view(self, **kwargs):
         department = kwargs['instance']