New userprofile

fixes #364.

tests are green and evap-dev is running with the migrated data. 
that was part of my process, explicitly static it and later setting it in the settings, and i forgot to change it back.

but while we're at it... doing this consistently would mean to replace all `UserProfile` occurrences in relations with `settings.AUTH_USER_PROFILE` as you said but additionally we'd need to replace all other occurrences with `get_user_model()`.

Should i do that? I mean, the only reason stated in the docs is 
"If you reference User directly (for example, by referring to it in a foreign key), your code will not work in projects where the AUTH_USER_MODEL setting has been changed to a different User model."
 which is not a valid argument for us as our four core apps are not meant for re-using them somewhere else.