Revise Purifier to pass input straight to output if null/false/0/etc.
Un-revert  "Revise URL::query() to use Purifier on passed $params" since Purifier is fixed.
Add class_exists() before method_exists() in ORM overload.
Change two DB calls to ORM calls so we can use with() instead of join().
Tweak DB call in GalleryTask to select "id" instead of "item.id".
Add Purifier unit test to check passing empty values.
Merge pull request #314 from shadlaws/purifier_query_db_20130424

Purifier query db 20130424