/* From the DM Reference for appearance: 
Other vars that are technically part of the appearance, 
but don't make any sense to change when cloning, are not changed. 
These include density, dir, screen_loc, and verbs. 
However, those vars ARE copied when you assign a /mutable_appearance. 
*/
mob/Login()
    var obj/o = new
    o.dir = 4
    var mutable_appearance/ma = new (o)
    ASSERT(ma.dir == 4) // succeeds (good)
    o.dir = 2
    o.appearance = ma
    ASSERT(o.appearance:dir == 4) // ...succeeds (ok?)
    ASSERT(o.dir == 4) // fails (bad)