As it turned out this is simply too dangerous - these should be left to be loaded from the map data or set manually.
All remaining setups using this feature have either been moved to Initialize or other meta properties that are not affected by map loading.
Order of application with map sprites was not correct.
This also simplifies how the defaults are stored - the separate data is gone, they now use the regular defaults.
They cannot be parsed directly into the actor's sprite because that gets used in ways that require a different setup.
This alsp adds a property parser and a setter function for the SpriteSet array. The idea here is to write code that does not need to use actual tile indices so it can later be refactored to real textures.
The idea here is to abstract picnum manipulation. Since all this is strongly index based it translates poorly to a system with named textures.
This allows a class to define a set of sprite images it intends to operate on as if it was still a simple indexed resource, even if the underlying storage changes.
