----------------
- Align CSS classes between AT and z3cform templates.
[thet]
- Allow empty values when the field is not required.
https://github.com/plone/plone.app.contenttypes/issues/79
[pbauer]
- Replace deprecated test assert statements.
[timo]
- Re-Add rendering of hidden date-, month- and year-fields for monthyear and
year widgets. This got lost at template unifying attempt.
[thet]
- In z3c.form based widgets, allow timezone naive datetime conversion.
[thet]
- If plone.schemaeditor is available, use his patched IDate schema.
[do3cc]