refactor 'dir = ' into 'set_dir()'

This should have little/no gameplay effect right now, just paving the
 way for directional lights.
Replaced handle_rotation() on buckly things with this.

Signed-off-by: Mloc-Argent <colmohici@gmail.com>

code/modules/power/singularity/particle_accelerator/particle_control.dm

@@ -157,7 +157,7 @@
 
 /obj/machinery/particle_accelerator/control_box/proc/part_scan()
 	for(var/obj/structure/particle_accelerator/fuel_chamber/F in orange(1,src))
-		src.dir = F.dir
+		src.set_dir(F.dir)
 	connected_parts = list()
 	var/tally = 0
 	var/ldir = turn(dir,-90)