Converts some istype's to use helpers (#3224)

Converts various istype's to use helpers. Mainly:
Cable
Wrench
Screwdriver
Multitool
Crowbar
Wirecutter

And makes the helpers defines.

code/modules/mob/living/bot/bot.dm

@@ -87,14 +87,14 @@
 			else
 				user << "<span class='warning'>Access denied.</span>"
 		return
-	else if(istype(O, /obj/item/weapon/screwdriver))
+	else if(isscrewdriver(O))
 		if(!locked)
 			open = !open
 			user << "<span class='notice'>Maintenance panel is now [open ? "opened" : "closed"].</span>"
 		else
 			user << "<span class='notice'>You need to unlock the controls first.</span>"
 		return
-	else if(istype(O, /obj/item/weapon/weldingtool))
+	else if(iswelder(O))
 		if(health < maxHealth)
 			if(open)
 				health = min(maxHealth, health + 10)

code/modules/mob/living/bot/ed209bot.dm

@@ -113,7 +113,7 @@
 				return 1
 
 		if(3)
-			if(istype(W, /obj/item/weapon/weldingtool))
+			if(iswelder(W))
 				var/obj/item/weapon/weldingtool/WT = W
 				if(WT.remove_fuel(0, user))
 					build_step++
@@ -143,7 +143,7 @@
 				return 1
 
 		if(6)
-			if(istype(W, /obj/item/stack/cable_coil))
+			if(iscoil(W))
 				var/obj/item/stack/cable_coil/C = W
 				if (C.get_amount() < 1)
 					user << "<span class='warning'>You need one coil of wire to wire [src].</span>"
@@ -168,7 +168,7 @@
 				return 1
 
 		if(8)
-			if(istype(W, /obj/item/weapon/screwdriver))
+			if(isscrewdriver(W))
 				playsound(src.loc, 'sound/items/Screwdriver.ogg', 100, 1)
 				var/turf/T = get_turf(user)
 				user << "<span class='notice'>Now attaching the gun to the frame...</span>"

code/modules/mob/living/bot/secbot.dm

@@ -524,7 +524,7 @@
 
 /obj/item/weapon/secbot_assembly/attackby(var/obj/item/O, var/mob/user)
 	..()
-	if(istype(O, /obj/item/weapon/weldingtool) && !build_step)
+	if(iswelder(O) && !build_step)
 		var/obj/item/weapon/weldingtool/WT = O
 		if(WT.remove_fuel(0, user))
 			build_step = 1