Ports Goonchat from Baystation. (#9635)

changes:

    rscadd: "Ported a new chat system, Goonchat, that allows for cool things like changing font style, size, spacing, highlighting up to 5 strings in the chat, and DARK MODE."
    rscadd: "Repeated chat messages can now get compacted. You can disable this in goonchat settings."
    rscadd: "You can change icon style to any font on your system."
    tweak: "The game window has been altered a bit to adjust for this."
    rscdel: "Removed skin style prefs as they are no longer used."

code/controllers/subsystems/ping.dm

@@ -0,0 +1,32 @@
+/datum/controller/subsystem/ping
+	name = "Ping"
+	priority = SS_PRIORITY_PING
+	wait = 3 SECONDS
+	flags = SS_NO_INIT | SS_FIRE_IN_LOBBY
+
+	var/list/currentrun = list()
+
+/datum/controller/subsystem/ping/stat_entry()
+	..("P:[clients.len]")
+
+
+/datum/controller/subsystem/ping/fire(resumed = 0)
+	if (!resumed)
+		src.currentrun = clients.Copy()
+
+	//cache for sanic speed (lists are references anyways)
+	var/list/currentrun = src.currentrun
+
+	while (currentrun.len)
+		var/client/C = currentrun[currentrun.len]
+		currentrun.len--
+
+		if (!C || !C.chatOutput || !C.chatOutput.loaded)
+			if (MC_TICK_CHECK)
+				return
+			continue
+
+		// softPang isn't handled anywhere but it'll always reset the opts.lastPang.
+		C.chatOutput.ehjax_send(data = C.is_afk(29) ? "softPang" : "pang")
+		if (MC_TICK_CHECK)
+			return