Doors and possibly A_Dormant use a smaller radius check for monsters

[Braden Obrzut]

As noted in #283: Doors should be able to close on monsters based on treating them as if their radius was 22 like the player. A monster standing on a tile behind a door (as is the case with Hans in E1L9) should not prevent the door from automatically closing.

A_Dormant also used MINDIST (22) to determine what tiles to check for other monsters, and may need adjustment. In this case interaction with player is based on MINACTORDIST so the radius check against the player is fine.