- Slight update to Edit Employee so that updating an employee doesn't
fail with a message about duplicate tax id, if the id is assigned to the
employee being updated.
- Updated DBInterface::isTaxIdInUse() to return the ID of the employee
the tax ID is assigned to, so it can be used when updating to determine
if there is actually a collision.
- Updated My Pay to display a message if no pay stubs are available for
the employee.