More material renames

Gives several materials shorter and easier to type names, updating the
display_name where applicable. Also fixed a slightly mismatched variable
type.

code/game/objects/items/robot/robot_parts.dm

@@ -126,7 +126,7 @@
 /obj/item/robot_parts/robot_suit/attackby(obj/item/W as obj, mob/user as mob)
 	..()
 	if(istype(W, /obj/item/stack/material) && W.get_material_name() == DEFAULT_WALL_MATERIAL && !l_arm && !r_arm && !l_leg && !r_leg && !chest && !head)
-		var/obj/item/stack/material/steel/M = W
+		var/obj/item/stack/material/M = W
 		if (M.use(1))
 			var/obj/item/weapon/secbot_assembly/ed209_assembly/B = new /obj/item/weapon/secbot_assembly/ed209_assembly
 			B.loc = get_turf(src)

code/game/objects/items/weapons/material/shards.dm

@@ -87,4 +87,4 @@
 	..(loc, "steel")
 
 /obj/item/weapon/material/shard/phoron/New(loc)
-	..(loc, "phoron glass")
+	..(loc, "phglass")