V0.5 fixes first cheese discovered by boaan

This update implements a solution to a "cheese" discovered by Boaan, creator of Volatile (https://boaan.itch.io/), where the player could use one marble to block a closing door, then release the door button and ram their way through with both marbles. This fix detects whether a button is being pressed for the door. If not, the door will apply force to marbles pushing them away when they attempt to jam them open.

Thanks Boaan!