Refactor #936

Updated by Alexander Watzinger 4 months ago

Dates will be completely rewritten. Mostly but not only for performance reasons, among other things code will be easier readable, import/export will be much easier and so on.

Dates will be saved in additional fields of the model.entity entity table instead of being own entities. There will be only from and to dates (no "exact date" anymore, it is exact automatically if there is only a from date).

Since the date check functions have to be rewritten too an additional check if actors participated at an event before their birth or after death will be added when we are at it.