10_0000th bit of Flag0 is to indicate if an item was dropped rather than placed (dropped clothing vs clothing on display)
treat dropped items and buried item sizes as 2x2 (1.0x1.0) rather than their placed sizes
Different means of expression for the 8 byte item structure's FreeParam
Will be expanding the ItemEditor so that it has a checkmark to toggle Extension Item editing behavior.
Removes IHeldItem as there's no need to abstract it.
Move sprite resources to subfolder for organization
Add FieldItem class (replaces MapItem), might work in a field item editor (similar to building editor)
