Only-on-terrain objects only render on one-way-capable terrain

[Nami Verasche]

http://www.lemmingsforums.net/index.php?topic=2671.0

Fixed in the latest experimental code for the player, but remains a bug in the editor. Marked as "major" for priority because the primary use of such is decoration, which is very problematic if they can't be seen properly.

[Nami Verasche]

Fixed the code. However, won't include this fix for now, as stable NL also has this bug.