Code rework of placing things on walls.

Stuff goes under types.
Types have procs.
Never have 500 lines of repeated code again.

I came very close to crying while editing this. You should appreciate
that.

----

This commit entirely reworks how placing things on walls work- Posters
have intentionally been left alone to reduce the amount of lines
changed. With this commit, wall-mounted objects are no longer snowflaked
into the wall file.

code/game/objects/items/mountable_frames/lights.dm

@@ -0,0 +1,39 @@
+/obj/item/mounted/frame/light_fixture
+	name = "light fixture frame"
+	desc = "Used for building lights."
+	icon = 'icons/obj/lighting.dmi'
+	icon_state = "tube-construct-item"
+	var/fixture_type = "tube"
+	mount_reqs = list("simfloor")
+
+/obj/item/mounted/frame/light_fixture/do_build(turf/on_wall, mob/user)
+	user << "You begin attaching [src] to \the [on_wall]."
+	playsound(get_turf(src), 'sound/machines/click.ogg', 75, 1)
+	var/constrdir = user.dir
+	var/constrloc = get_turf(user)
+	if (!do_after(user, 30))
+		return
+	var/obj/machinery/light_construct/newlight
+	switch(fixture_type)
+		if("bulb")
+			newlight = new /obj/machinery/light_construct/small(constrloc)
+		if("tube")
+			newlight = new /obj/machinery/light_construct(constrloc)
+		else
+			newlight = new /obj/machinery/light_construct/small(constrloc)
+	newlight.dir = constrdir
+	newlight.fingerprints = src.fingerprints
+	newlight.fingerprintshidden = src.fingerprintshidden
+	newlight.fingerprintslast = src.fingerprintslast
+
+	user.visible_message("[user] attaches \the [src] to \the [on_wall].", \
+		"You attach \the [src] to \the [on_wall].")
+	qdel(src)
+
+/obj/item/mounted/frame/light_fixture/small
+	name = "small light fixture frame"
+	desc = "Used for building small lights."
+	icon = 'icons/obj/lighting.dmi'
+	icon_state = "bulb-construct-item"
+	fixture_type = "bulb"
+	sheets_refunded = 1