Changeset 2f3b3c6c1190 adds the version range check to django_v2 to block it past 3.5.

I didn't add the django_v3 quite yet because I didn't realize that Django 1.8 won't work without being manually patched by us (I thought that issue was limited to our Django 1.5 copy). I did check and the issue is fixed in Django 1.9 which is due before the end of the year: https://code.djangoproject.com/wiki/Version1.9Roadmap .

Since this is for Python 3.6 which is in no way close to coming out I say we simply wait until Django 1.9.0 is released and then introduce django_v3 without having to keep our own patched version of Django around.