First pass on wall refactor/mining changes.

code/modules/mining/mineral_effect.dm

@@ -0,0 +1,14 @@
+/obj/effect/mineral
+	name = "mineral vein"
+	icon = 'icons/obj/mining.dmi'
+	desc = "Shiny."
+	mouse_opacity = 0
+	density = 0
+	anchored = 1
+
+/obj/effect/mineral/New(var/newloc, var/mineral/M)
+	..(newloc)
+	name = "[M.display_name] deposit"
+	icon_state = "rock_[M.name]"
+	var/turf/T = get_turf(src)
+	layer = T.layer+0.1