TG: - Added basic heavy-duty cables, they cannot be destroyed with wirecutters,

unfortunately they currently cannot be created either. Not present anywhere on
the map yet.
- Fixed a bug with masks, which did not follow the equipment rules of the
SLOT_MASK flag.
- Fixed a problem where monkeys could not equip a backpack.
Revision: r3774
Author: 	 baloh.matevz

TG: - Added the heavy cable sprites, sprited by Thunder11.
Revision: r3775
Author: 	 baloh.matevz

code/modules/mob/living/carbon/human/human.dm

@@ -547,7 +547,7 @@
 				if (emptyHand)
 					wear_mask.DblClick()
 				return
-			if (!( istype(W, /obj/item/clothing/mask) ))
+			if (!( W.slot_flags & SLOT_MASK ))
 				return
 			u_equip(W)
 			wear_mask = W

code/modules/mob/mob.dm

@@ -90,15 +90,20 @@
 		if("mask")
 			if (wear_mask)
 				return
-			if (!( istype(W, /obj/item/clothing/mask) ))
+			if (!( W.slot_flags & SLOT_MASK ))
 				return
 			u_equip(W)
 			wear_mask = W
 			W.equipped(src, text)
 		if("back")
-			if ((back || !( istype(W, /obj/item/weapon) )))
+			if (back)
 				return
-			if (!( W.flags & 1 ))
+			if (!istype(W, /obj/item))
+				return
+			if (!( W.slot_flags & SLOT_BACK ))
+				return
+			if(istype(W,/obj/item/weapon/twohanded) && W:wielded)
+				usr << "<span class='warning'>Unwield the [initial(W.name)] first!</span>"
 				return
 			u_equip(W)
 			back = W

code/modules/power/cable_heavyduty.dm

@@ -0,0 +1,27 @@
+/obj/item/weapon/cable_coil/heavyduty
+	name = "heavy cable coil"
+	icon = 'power.dmi'
+	icon_state = "wire"
+
+/obj/structure/cable/heavyduty
+	icon = 'power_cond_heavy.dmi'
+	name = "large power cable"
+	desc = "This cable is tough. It cannot be cut with simple hand tools."
+
+/obj/structure/cable/heavyduty/attackby(obj/item/W, mob/user)
+
+	var/turf/T = src.loc
+	if(T.intact)
+		return
+
+	if(istype(W, /obj/item/weapon/wirecutters))
+		usr << "\blue These cables are too tough to be cut with those [W.name]."
+		return
+	else if(istype(W, /obj/item/weapon/cable_coil))
+		usr << "\blue You will need heavier cables to connect to these."
+		return
+	else
+		..()
+
+/obj/structure/cable/heavyduty/cableColor(var/colorC)
+	return