* Allow callable in copy default
* Support dotted notation in copy default
* Use setdefault in copy
* Copy default when needed
* Do not set default state in copy
* Use callable and dotted notation in copy default
issue5576
issue7648
review72291002
The default value of copy is expected to be the same format as for the default
methods. So the value for xxx2Many fields must be converted.
issue6818
review37751002