Adding improvised signal jammers

Adds improvised signal jammers, does a bit of light refactoring, makes
signal jammers stop radio signallers.

code/modules/assembly/signaler.dm

@@ -99,8 +99,12 @@
 
 
 	proc/signal()
-		if(!radio_connection) return
-
+		if(!radio_connection) 
+			return
+		
+		if(within_jamming_range(src)) // can't send a signal through jammers
+			return
+			
 		var/datum/signal/signal = new
 		signal.source = src
 		signal.encryption = code
@@ -126,6 +130,8 @@
 
 
 	receive_signal(datum/signal/signal)
+		if(within_jamming_range(src)) // can't receive signals while jammed
+			return 
 		if(!signal)	return 0
 		if(signal.encryption != code)	return 0
 		if(!(src.wires & WIRE_RADIO_RECEIVE))	return 0
@@ -166,4 +172,4 @@
 		set desc = "BOOOOM!"
 		deadman = 1
 		processing_objects.Add(src)
-		usr.visible_message("\red [usr] moves their finger over [src]'s signal button...")
+		usr.visible_message("\red [usr] moves their finger over [src]'s signal button...")

code/modules/mob/inventory.dm

@@ -102,6 +102,13 @@
 		return 1
 	return 0
 
+	
+/mob/proc/drop_item_if_in_either_hand(var/obj/item/W,var/atom/Target)
+	if (l_hand==W)
+		return drop_l_hand(Target)
+	if (r_hand==W)
+		return drop_r_hand(Target)
+		
 
 //Drops the item in our left hand
 /mob/proc/drop_l_hand(var/atom/Target)

code/modules/power/cell.dm

@@ -89,8 +89,15 @@
 			message_mods("[user.name] ([user.ckey]) injected a power cell with plasma, rigging it to explode.")
 
 		S.reagents.clear_reagents()
-
-
+		
+	if(istype(W,/obj/item/device/assembly_holder))
+		var/obj/item/device/assembly_holder/holder = W
+		if(istype(holder.a_left,/obj/item/device/assembly/signaler) && istype(holder.a_right,/obj/item/device/assembly/signaler))
+			user << "<span class='notice'>You make an improvised signal jammer from \the [holder].</span>"
+			new /obj/item/device/radiojammer/improvised(holder,src,user)
+			
+			
+		
 /obj/item/weapon/cell/proc/explode()
 	var/turf/T = get_turf(src.loc)
 /*