done fixing errors in output from CollosionTrin.toExportString (I forgot to increment 'ey' if 'y' = 'ey')

fcore/quad-tree.sml

@@ -536,6 +536,8 @@ struct
 
   fun toExportStringFolder ({x, ex, y, ey, data = {r, g, b, a}}, acc) =
     let
+      val ey = if ey = y then y + 1 else ey
+
       val x = makeXString x
       val y = makeYString y
       val ex = makeEndXString (x, ex)