PPos is best thought of as a cell grid applied in
screen space. Multiple cells with different
terrain heights may be projected to the same PPos,
or to multiple PPos if they do not align with the
screen grid.
PPos coordinates are used primarily for map edge
checks and shroud / visibility queries.
The actor and smudge definitions are now stored
as raw MiniYamlNodes in the map. It is now the
responsibility of the consumers to parse these
into real objects.
Improve error handling; fix utility command description
Revert output location to working directory for both map importers
Rework how the map tiles get populated
Remove actor comments
