Make faceted navigation configuration work for dexterity Items, not only Containers. Items do not implement getitem access, therefore we get a NotFound and not a KeyError when trying to get the 'at_widget_%s' customization element - see Products/Archetypes/generator/widget.py
changelog
Merge pull request #19 from sunew/fix-dext-item

Make faceted navigation configuration work for dexterity Items