Remove door crush damage for polymorphed critters

[Sundance]

I don't think door crushing needs to be done away with. I just don't think it should be the default setting. Let it be another option the AI can tamper with on his doors (with the same warning as shocking) along with being hacked. Doors still close on critters (because mob code is whacky) but it doesn't do any damage unless the ai/someone else has tampered with it.