Shorter Desiccant Bin and Lid

When using the Polydrier mod I wasn't happy with the airflow not passing over the desiccant bin as it's designed position is at the opposite end of the drybox. Modified the original design and added some airflow slots to the underside of the bin and reduced its height so it would fit above the containers original lid where the large round bung sits. This results in the warm air from the Polydrier passing directly over the desiccant bin which will both dry the filament and the desiccant more effectively. Added bonus of the hygrometer now being at the opposite end from the blown air so I have a better idea of the coldest part of the drybox temperature instead of it getting the warmest air.