
 [1] Item Decay Criteria
     An Item is allowed to decay if ALL of the following are true:
        - it is not In Use
        - it is Movable, OR it is a Corpse
        - its 'decayat' member is nonzero 
            AND the Game Clock has passed this 'decayat' time
        - it is not supported by a multi,
            OR its itemdesc.cfg entry specifies 'DecaysOnMultis 1'
        - it itemdesc.cfg entry specifies no 'DestroyScript', 
            OR its 'DestroyScript' returns nonzero.

 [2] Decay Action
     Container contents are moved to the ground at the Container's location
     before destroying the container.


 [3] Decay Sweep
     Each 64x64 tile World Zone is checked for decay approximately
     once every 10 minutes

