Mountable frame bugfixes and minor refactor (#13076)

* initial

* bit of code cleanup / refactoring

* review changes

* CRLF to LF

* GLOB stuff

* travis did not like that

Co-authored-by: SteelSlayer <SteelSlayer@users.noreply.github.com>

code/modules/power/apc.dm

@@ -147,7 +147,7 @@
 	if(terminal)
 		terminal.connect_to_network()
 
-/obj/machinery/power/apc/New(turf/loc, ndir, building = 0)
+/obj/machinery/power/apc/New(turf/loc, direction, building = 0)
 	if(!armor)
 		armor = list("melee" = 20, "bullet" = 20, "laser" = 10, "energy" = 100, "bomb" = 30, "bio" = 100, "rad" = 100, "fire" = 90, "acid" = 50)
 	..()
@@ -158,12 +158,11 @@
 	// offset 24 pixels in direction of dir
 	// this allows the APC to be embedded in a wall, yet still inside an area
 	if(building)
-		setDir(ndir)
-	tdir = dir		// to fix Vars bug
-	setDir(SOUTH)
+		setDir(direction) // We set this to direction only for pixel location determination.
+
+	set_pixel_offsets_from_dir(24, -24, 24, -24) // Set pixel offsets based on `dir`
+	setDir(SOUTH) // APC's should always appear to *face* south.
 
-	pixel_x = (src.tdir & 3)? 0 : (src.tdir == 4 ? 24 : -24)
-	pixel_y = (src.tdir & 3)? (src.tdir ==1 ? 24 : -24) : 0
 	if(building)
 		area = get_area(src)
 		area.apc |= src