Inject seo translations to prevent IntegrityError.

[vinnyrose]

Fixes #47

[vdboor]

This is an interesting approach to the problem, but I expect it won't work if you have multiple page models that inherit from HtmlPage (which I have).

Secondly, I'm considering to turn the derived models into proxy models too, as RedirectNode and FluentPage no longer have any relevant model fields of their own. Everything has moved into translatable fields, so those models only have the effect or selecting a subset of nodes, through an expensive join.

[vdboor]

If django-parler has on_delete=models.CASCADE, this problem would also not exist. Do you think there are drawbacks to that solution?

[vinnyrose]

I think 959211c is a fine workaround for this. Anything else will likely be fragile and have many edge cases.