Light fixture code cleanup & spooking (#14396)

* Autumn cleaning

* A few things I missed

* Set 'update' back to 'FALSE'

* Allows ghosts to burn out lights

And also tweaks the adminverb 'Fix all Lights' to reset the 'switchcount'.

* Tweaks burnout value

* A few more tweaks

* Removed an else

* I thought I'd already done this, guess not!

code/modules/admin/topic.dm

@@ -2925,6 +2925,7 @@
 				message_admins("[key_name_admin(usr)] fixed all lights", 1)
 				for(var/obj/machinery/light/L in GLOB.machines)
 					L.fix()
+					L.switchcount = 0
 			if("floorlava")
 				feedback_inc("admin_secrets_fun_used", 1)
 				feedback_add_details("admin_secrets_fun_used", "LF")