Fixes communicator newsfeed app. (#6713)

* Fixes communicator newsfeed app.
Fixes non-terminal while loop in get_latest_news(), helper.dm
Newscaster posts now have a world.time-esque timestamp number, so they can be (almost) uniquely identified

* whoopsie

code/game/objects/items/devices/communicator/UI.dm

@@ -122,6 +122,8 @@
 	data["manifest"] = PDA_Manifest
 	data["feeds"] = compile_news()
 	data["latest_news"] = get_recent_news()
+	if(newsfeed_channel)
+		data["target_feed"] = data["feeds"][newsfeed_channel]
 	if(cartridge) // If there's a cartridge, we need to grab the information from it
 		data["cart_devices"] = cartridge.get_device_status()
 		data["cart_templates"] = cartridge.ui_templates
@@ -280,6 +282,9 @@
 		var/obj/O = cartridge.internal_devices[text2num(href_list["toggle_device"])]
 		cartridge.active_devices ^= list(O) // Exclusive or, will toggle its presence
 
+	if(href_list["newsfeed"])
+		newsfeed_channel = text2num(href_list["newsfeed"])
+
 	if(href_list["cartridge_topic"] && cartridge) // Has to have a cartridge to perform these functions
 		cartridge.Topic(href, href_list)