Removes unsimulated turfs.

Moves shuttle turfs to paths under /turf/simulated/floor and /turf/simulated/wall
Players can now safely build on top of shuttle turfs
Fixes #1711
Adds several but not all paths for the different types of floor turfs, most of them in plasteel_floor.dm
The turf pathings are still in need of a deeper organization, but this is at least a start

code/modules/shuttle/shuttle.dm

@@ -302,8 +302,6 @@
 
 	for(var/i=1, i<=L0.len, ++i)
 		var/turf/T0 = L0[i]
-		if(!istype(T0, /turf/simulated/shuttle))	//only move shuttle turfs!
-			continue
 
 		var/turf/T1 = L1[i]
 		if(!T1)