RFC: exclude employees with a specific item completed

Filter the employeeview to only show employees who don't have a specific item completed.

Click on a checklist item in a user's list to see the filtered employeeview. A future diff will add a drop-down/combobox with all checklist items on the employeeview itself.

Is this code good enough? Are things badly named (rename ‘without_item’ to ‘incomplete_item’)?