Document the dynamic use of ModelForms classes

[jdetaeye]

Dynamically creating model forms is a fairly common use case, especially for users of the deprecated form_for_model and form_for_instance methods.
The modelforms class easily allows this, but the correct way to achieve it is not very obvious (except to more advanced Python programmers).
Documenting the right way should overcome this...

[jdetaeye]

modelforms documentation update

[Brian Rosner]

I disagree this is a common case. The reason the ModelForm class was created was to avoid this entirely and to leave people who still needed this functionality to either learn it or just use it outside the framework. I am closing this ticket because this shouldn't be described in the docs and would be better in the wiki since it is a special case. Plus this is simply Python. People can use django-users to get at learning how or just searching Google.