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/research/xenoarchaeology/tools/suspension_generator.dm

@@ -322,7 +322,7 @@
 	if(anchored)
 		usr << "\red You cannot rotate [src], it has been firmly fixed to the floor."
 	else
-		dir = turn(dir, 90)
+		set_dir(turn(dir, 90))
 
 /obj/machinery/suspension_gen/verb/rotate_cw()
 	set src in view(1)
@@ -332,7 +332,7 @@
 	if(anchored)
 		usr << "\red You cannot rotate [src], it has been firmly fixed to the floor."
 	else
-		dir = turn(dir, -90)
+		set_dir(turn(dir, -90))
 
 /obj/effect/suspension_field
 	name = "energy field"

code/modules/research/xenoarchaeology/tools/tools_locater.dm

@@ -22,7 +22,7 @@
 
 /obj/item/device/beacon_locator/process()
 	if(target_radio)
-		dir = get_dir(src,target_radio)
+		set_dir(get_dir(src,target_radio))
 		switch(get_dist(src,target_radio))
 			if(0 to 3)
 				icon_state = "pinondirect"