Request to add changes to ``model_to_dict`` in Django 1.10 to the release notes

[Aaron Lelevier]

It seems that the django.forms.models.model_to_dict function changed with the way that it treats many-to-many related objects. Before, it was returning them in a list if ID's. Not it's returning them as a queryset.

Commit that caused the change:

​https://github.com/django/django/commit/ded502024191053475bac811d365ac29dca1db61

The logic is here in the model_to_dict method:

​https://github.com/django/django/blob/1.10/django/forms/models.py#L91

And here in the field method:

​https://github.com/django/django/blob/1.10/django/db/models/fields/related.py#L1564-L1570

I'd like to request to add this to the release notes for Django 1.10. I couldn't find any note of it in there. I didn't know about the change, and it caused some code to break. No big deal, was able to locate the issue. Just want to point it out in case others may experience it.

Thank you

[Tim Graham]

We don't normally document private API changes, however, my sense is that model_to_dict() is widely used even though it's not documented. How about:

* Private API ``django.forms.models.model_to_dict()`` returns a queryset for
  ``ManyToManyField``\s rather than a list of IDs.

[Tim Graham <timograham@…>]

In f4b1f972:

Fixed #26999 -- Documented model_to_dict() ManyToManyField change in 1.10.

[Tim Graham <timograham@…>]

In b00a3f17:

[1.10.x] Fixed #26999 -- Documented model_to_dict() ManyToManyField change in 1.10.

Backport of f4b1f972dc69e519a78182353e43701a17bb43aa from master