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- Use a *set* of choice fields for the "multiple choice" field option in the UI,
instead of a *list* of choice fields. The latter is orderable and is a less
common use case (plus we need a better widget for it).
[davisagli]
- Make it possible for schema contexts to restrict the fields that can be added
by defining an allowedFields property.
[davisagli]
- Add more specific events for when a field is added or removed.
[davisagli]
- I18n improved by adding many missing strings
[giacomos]