Refactored how the sortable_by properties get populated by looping over the model fields until we get to the SortableForeignKey, then grabbing properties from the field and its related data.
Refactored ORM calls to properly order objects by the sortable_by property to ensure objects are grouped correctly in the sortable change list template after being passed through dynamic_regroup.
Fixed missing import for jquery.effects.core, again.
Refactored sortable_by classmethod into a property.