Add more stub files in startapp template

[Mark]

I find that the standard django app template (the one used by the startapp command) is a little bit "messy" and it seems to me that encourages not-so-clean architectures for the apps.

This is what I suggest:

• A separate forms.py file (to discourage keeping form classes in views.py file)
• Separate middleware.py and mixins.py files (for the same reason as above, and to make the third party app architectures more similar to django itself, with less doubts for the developer)
• A separate urls.py file (this is another file I find always creating myself just after the app creation)
• Refactor tests.py in a tests module, also to encourage modularity of the testsuite instead of creating a mammoth tests.py file by adding "just one more test case" and avoiding the hassle of refactoring the whole thing after some development

I forked the django project on github and created a branch in my repository, here: ​https://github.com/mcagl/django/tree/mcagl/better-startapp-template

The branch does not conflict with the master branch

[Tim Graham]

You can raise the idea on the DevelopersMailingList but past discussions (search that mailing list's archives for "startapp" and "startproject") to add files or reorganize has not yielded consensus about it -- that's why there's an option for custom project/app templates. The Django master branch no longer suppots Python 2, so # coding: utf-8 would be obsolete.

[Natalia Bidart]

Related to ticket #25943