Add multidatabase support

[davit555]

in case when you want to add this framework in already existing project with the separate database
it won't work
it will fallback to default database always

[auvipy]

did you try django multi db config?

[pembo13]

I too wanted to keep the activity in a separate database, but it doesn't work.

Because of the heavy reliance on contentypes a db router doesn't work. If you allow the contenttypes to be created in the secondary database, it's out of sync with the default database, and generic lookups fail. If you don't allow contenttpes in the secondary database, one gets errors since django_content_type does not exist.