Replaces typesof with subtypesof where applicable

code/modules/mining/materials.dm

@@ -13,7 +13,7 @@
 	var/list/datum/material/storage[0]
 
 /datum/materials/New()
-	for(var/matdata in typesof(/datum/material) - /datum/material)
+	for(var/matdata in subtypesof(/datum/material))
 		var/datum/material/mat = new matdata
 		storage[mat.id]=mat
 

code/modules/mining/minerals.dm

@@ -2,7 +2,7 @@ var/list/name_to_mineral
 
 proc/SetupMinerals()
 	name_to_mineral = list()
-	for(var/type in typesof(/mineral) - /mineral)
+	for(var/type in subtypesof(/mineral))
 		var/mineral/new_mineral = new type
 		if(!new_mineral.name)
 			continue

code/modules/mining/surprise.dm

@@ -3,7 +3,7 @@
 
 #define TURF_FLOOR 0
 #define TURF_WALL 1
-var/global/list/mining_surprises = typesof(/mining_surprise)-/mining_surprise
+var/global/list/mining_surprises = subtypesof(/mining_surprise)
 
 /surprise_turf_info
 	var/list/types[0]