-------------------
- Replace "is_sl_contentish" function with "belongs_to_parent".
This requires an update of `ftw.publisher.sender` to the compatible
version. The new implementation is more generic. [jone]
- Replace the Simplelayout-specific "RemoveDeletedSLContentishChildren"
adapter with a generic "RemoveChildren" adapter so that it also works
for other kind of content, such as PloneFormGen. [jone]
- Improve ``ftw.trash`` integration regarding deleted content. [jone]