Minor formatting changes.
Cahnged check for sortable_by_class_is_sortable to use new check_model_is_sortable, rather than only relying on the number of objects.
Added new get_permissions_codename check for permissions in upcoming Django 1.8.
Refactored all version checks. All checks are done in tuple format instead of checking for a django major and minor version number.
Removed unused RequestFactory in tests.
Added NonSortableParentAdmin class to enable sorting URLs and JavaScript on models that do not inherit from Sortable.
Removed unused 'ordering' property on SortableAdmin.
Changed assignment of sorting_filters to use getattr, enabling NonSortableParentAdmin to inherit from SortableAdminBase.
Moved template properties to SortableAdminBase.
Updated readme.
Updated sample project to leverage new sorting_filters on Person model and admin.
Removed custom change list template for Person admin.
Passing `mimetype` to an HttpResponse object is deprecated
since Django 1.5 and will throw an error in Django 1.7.
`content_type` is supported since Django 1.0.
Fixed a problem with the detection of sortability of inline models at the template level that was preventing the drag-and-drop messaging in the template to be displayed.
Updated unit tests.
Updated version to 1.4.5.
Updated README with explanation of requirements for overriding queryset() on inline models.
Added extra models to sample project to demonstrate sortable models with custom querysets.
Improved JavaScript of sortables to be more efficient with better comparison checking.
Fixed highlighting of stacked inlines on sort finish.
Updated status to stable/production.
Added AttributeError exception handling for models that specify a SortableForeignKey that does not inherit from Sortable.
Added template support for nested objects that are sortable by a foreign key, where the foreign key is not sortable.
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.
Added backwards compatibility for pre 1.1.1 versions that still have sortable_by defined as a classmethod.
Need to address dynamic regroup template tag to see why categories are not being grouped properly in sample app.