Adjust DEFAULT_OPTIONS to reflect normalization algorithm
Add docstring
Remove unsupported options from defaults
Add unsortable_columns to options normalization
Remove redundant check
Implement use of new utility
Implement use of new utility
Misc error
Switch to testing "id" instead of "pk"

“pk” is one of those fields that’s not really a field, and doesn’t show
up in the standard Model._meta lists.
Add DatatableOptions validation tests