Add car/ghost render dist

TODO.txt

@@ -1,6 +1,7 @@
 =========== GENERAL ==============
 
-- ghost visible distance
+- force chunk reload upon map restart so that there's no blinking at start
+- make a small txt game menual
 - test if the replay stretching works
 - replay validation
 - ghosts: if the replay for the ghost is too long (too many samples for the
@@ -24,16 +25,20 @@
 
 =========== BUGS =================
 
-- why does the ghost stop in front of the finish?
+- starting test replay two twice in a row breaks it
 - drawing dithered transparent objects fills z-buffer in the transparent parts
   and then the geometry behind it isn't drawn <- PARTIALLY FIXED NOW
 
 =========== HANDLED ==============
 
 - allow stopping car rotation in air like in Trackmania
+- ghost visible distance -- maybe even car should have this (watching rep with
+  free camera)? maybe generalize setCar/GhostVisibility to
+  setCarGhostVisibilityDistance where 0 means make invisible?
 - add time slow down setting
 - the horizon on background seems too low? maybe add setting to shift it a bit?
 - replay format
+- why does the ghost stop in front of the finish?
 - prevent time overflow! stop incrementing level frame once it's at maximum
 - car shadow? probably would have to be done as screen space effect with
   z-buffer (shadow as 3D model would require collision detection and would make