Fix openturf starlight (#3401)

changes:

Openturf starlight now actually works.
Openturf starlight is now under its own config option, so it can be toggled separately from starlight.
OT starlight no longer re-applies to a turf that already has it set.
Seems to use a fair bit of memory unfortunately, as well as adding a good 25 seconds or so to boot time.

code/controllers/configuration.dm

@@ -275,6 +275,8 @@ var/list/gamemode_cache = list()
 
 	var/show_game_type_odd = 1 // If the check gamemode probability verb is enabled or not
 
+	var/openturf_starlight_permitted = FALSE
+
 /datum/configuration/New()
 	var/list/L = typesof(/datum/game_mode) - /datum/game_mode
 	for (var/T in L)
@@ -741,6 +743,9 @@ var/list/gamemode_cache = list()
 					value = text2num(value)
 					config.starlight = value >= 0 ? value : 0
 
+				if("openturf_starlight")
+					openturf_starlight_permitted = TRUE
+
 				if("ert_species")
 					config.ert_species = text2list(value, ";")
 					if(!config.ert_species.len)