Replace deletes with select/update statements

In our environment, we have an automated testing platform. The volume of deletes/inserts happening was quite large and were happening regardless of whether or not a change to the URL alias was actually made. This resulted in some bizarre errors related to the workbench_moderation module and it's re-save of a node using a PHP shutdown hook. The attached patch replaces the delete/insert logic with a select that then checks to see if data has changed.