To provide easily usage of model and flexible fields overwritten,
this commit changes defaults to hidden maps and update/overwrite with
client defined map.
After this commit, serialization behaviors would be changed if user
uses empty map to disable custom serialization so the version would
bump into 0.2.0.
The defaults are all discarded when there is custom serializer for partial field and break implicit convention of model usage. Check also: https://github.com/myyang/django-pb-model/issues/21
To provide easily usage of model and flexible fields overwritten, this commit changes defaults to hidden maps and update/overwrite with client defined map.
After this commit, serialization behaviors would be changed if user uses empty map to disable custom serialization so the version would bump into 0.2.0.