Take parameters to skip validations, define association ordering

If you're trying to maintain a particular sort order because of dependencies in a model's associations, it appears the better place to specify the sort order is in the model itself, rather than having to remember the right order every time you want to import.

This module already has a precedent of adding class methods to allow models to specify specific behavior. See for instance, `ClassMethods#overridden_import_attrs` in this file. You could introduce an `#association_import_order` to do the same thing.