Products.archetypes

--------------------

Fixes:

- Replace zope.tal.ndiff with difflib.ndiff. It was removed in zope.tal 4.0.0.
[pbauer]

--------------------

Fixes:

- White space only pep8 cleanup. Not in the skins.
[maurits]

- Removed code for unused types_link_to_folder_contents and
use_folder_tabs.
[maurits]

--------------------

- Pull types_link_to_folder_contents values from the configuration registry.
[esteele]

- Set calendar_starting_year and calendar_future_years_available in registry.
See https://github.com/plone/Products.CMFPlone/issues/872
[pbauer]

-------------------

- Defend `defaultRights` method against broken portal_metadata.
Its schemas are instances of CMFDefault classes, which normally are
no longer available in Plone 5. The relevant code has been
duplicated in ATContentTypes.
[maurits]

- Compare picklist entry value, not text.
[paulrentschler]

-------------------

- Moved createObject from ATContentTypes.
[tomgross]

-------------------

- Remove dependency on CMFDefault
[tomgross]

- We only support `utf-8` at the moment.
[tomgross]