Fallback for autoGroups group_name: if schema.__name__ is empty or None, try prefix (if available), finally fall back to None. This permits AutoExtensibleForm to support anonymous schema (usually dynamic schema) without a __name__ attribute.
doctest for AutoExtensibleForm support for using prefix in lieu of schema.__name__ when unavailable/empty
Merge pull request #6 from upiq/master

Support dynamic schema without __name__