Datagrids are now a bit less QuerySet-specific. They still take

QuerySet-like objects, but it's no longer necessary for them to support

distinct(), values_list(), or to have a model attribute.
This is primarily intended for use with Haystack's SearchQuerySet, which

can now be used to back the results of a datagrid. In this case, a

search result will be paginated, with each page turning into a typical

model query based on that page's IDs.

Tested with standard datagrids with a real Queryset, and with a SearchQuerySet.