Extension additions and multitool menu tweaks.

Relocates obj extension code to the extension file.
Adds a support method, set_extension, to ensure that proper cleanup occurs in the case of multiple additions to the same extension type.
The default multitool menu title is now much shorter.
The cloning computer multitool menu now lists all connected cloning pods.

code/datums/expansions/expansion.dm

@@ -1,7 +1,5 @@
 /datum/expansion
-
-/datum/expansion
-	var/atom/holder = null // The holder
+	var/datum/holder = null // The holder
 
 /datum/expansion/New(var/atom/holder)
 	if(!istype(holder))
@@ -22,3 +20,18 @@
 	if(CanUseTopic(usr) != STATUS_INTERACTIVE)
 		return 1
 	return 0
+
+/obj
+	var/list/datum/expansion/expansions = list()
+
+/obj/Destroy()
+	if(expansions)
+		for(var/expansion in expansions)
+			qdel(expansions[expansion])
+		expansions.Cut()
+	return ..()
+
+/obj/proc/set_expansion(var/type, var/instance)
+	if(expansions[type])
+		qdel(expansions[type])
+	expansions[type] = instance

code/datums/expansions/multitool/cloning.dm

@@ -1,5 +1,9 @@
 /datum/expansion/multitool/cryo/get_interact_window(var/obj/item/device/multitool/M, var/mob/user)
-	return buffer(M)
+	. += buffer(M)
+	. += "<HR><b>Connected Cloning Pods:</b><br>"
+	var/obj/machinery/computer/cloning/C = holder
+	for(var/atom/cloning_pod in C.pods)
+		. += "[cloning_pod.name]<br>"
 
 /datum/expansion/multitool/cryo/receive_buffer(var/obj/item/device/multitool/M, var/atom/buffer, var/mob/user)
 	var/obj/machinery/clonepod/P = buffer

code/datums/expansions/multitool/multitool.dm

@@ -17,9 +17,9 @@
 
 	var/html = get_interact_window(M, user)
 	if(html)
-		var/datum/browser/popup = new(usr, "multitool", holder.name, window_x, window_y)
+		var/datum/browser/popup = new(usr, "multitool", "Multitool Menu", window_x, window_y)
 		popup.set_content(html)
-		popup.set_title_image(user.browse_rsc_icon(holder.icon, holder.icon_state))
+		popup.set_title_image(user.browse_rsc_icon(M.icon, M.icon_state))
 		popup.open()
 	else
 		close_window(usr)
@@ -32,8 +32,9 @@
 
 /datum/expansion/multitool/proc/buffer(var/obj/item/device/multitool/multitool)
 	. += "<b>Buffer Memory:</b><br>"
-	if(multitool.buffer_name)
-		. += "[multitool.buffer_name] <a href='?src=\ref[src];send=\ref[multitool.buffer_object]'>Send</a> <a href='?src=\ref[src];purge=1'>Purge</a><br>"
+	var/buffer_name = multitool.get_buffer_name()
+	if(buffer_name)
+		. += "[buffer_name] <a href='?src=\ref[src];send=\ref[multitool.buffer_object]'>Send</a> <a href='?src=\ref[src];purge=1'>Purge</a><br>"
 	else
 		. += "No connection stored in the buffer."
 
@@ -78,8 +79,10 @@
 	return MT_NOACTION
 
 /datum/expansion/multitool/proc/send_buffer(var/obj/item/device/multitool/M, var/atom/buffer, var/mob/user)
-	if(M.get_buffer() == buffer)
+	if(M.get_buffer() == buffer && buffer)
 		receive_buffer(M, buffer, user)
+	else if(!buffer)
+		user << "<span class='warning'>Unable to acquire data from the buffered object. Purging from memory.</span>"
 	return MT_REFRESH
 
 /datum/expansion/multitool/proc/receive_buffer(var/obj/item/device/multitool/M, var/atom/buffer, var/mob/user)