Move django.contrib.formtools to own repo and packaged app

[Jannis Leidel]

As discussed in ​https://groups.google.com/d/topic/django-developers/cJyL87v3BWw/discussion the formtools contrib app should be moved out of Django and released as a separately maintained package on PyPI.

I'm opening this just as a matter of record keeping and to make sure all questions are answered.

[Jannis Leidel]

Here is what I've done already:

• moved the app into an own Git repo and pushed it to ​https://github.com/django/django-formtools (kept the Git history with some trickery and pokery)
• added files for packaging it
• ported over the docs from Django's own docs (​http://django-formtools.rtfd.org/)
• set up continuous integration based on Travis CI (​https://travis-ci.org/django/django-formtools)
• set up a Transifex project under the Django organization (​https://www.transifex.com/projects/p/django-formtools/)
• set up automatic code coverage testing (​https://coveralls.io/r/django/django-formtools)
• fixed a few broken translation strings

I'm tracking the rest of the issues for the actual app separately in the 1.0 milestone over at its new issue tracker: ​https://github.com/django/django-formtools/milestones/1.0

[Jannis Leidel]

Patch for the doc update here: ​https://github.com/django/django/pull/3385

[Tim Graham]

Docs look good to me. I left a link with some minor edits on the PR.

[Markus Holtermann]

Looks good to me.

[Tim Graham <timograham@…>]

In 6302893112a67343b3f5eff3f09f91b245346877:

Updated formtools docs to point at new package outside the Django repo.

Refs #23677.

[Tim Graham <timograham@…>]

In 14a3b60981f63334520c713bb3a2c9c694c49a1f:

Fixed #23677 -- Removed contrib.formtools