Hard upstream sync (#6951)

* maps - none of our changes included yet i'll get them in after i finish up the rest of the sync

* sync part 1 - underscore folders in code

* controllers folder

* datums folder

* game folder

* cmon, work

* modules - admin to awaymissions

* cargo to events

* fields to lighting

* mapping > ruins

* rest of the code folder

* rest of the folders in the root directory

* DME

* fixes compiling errors. it compiles so it works

* readds map changes

* fixes dogborg module select

* fixes typo in moduleselect_alternate_icon filepath

code/game/objects/items/devices/transfer_valve.dm

@@ -1,7 +1,6 @@
 /obj/item/transfer_valve
 	icon = 'icons/obj/assemblies.dmi'
 	name = "tank transfer valve"
-	icon = 'icons/obj/device.dmi'
 	icon_state = "valve_1"
 	item_state = "ttv"
 	lefthand_file = 'icons/mob/inhands/weapons/bombs_lefthand.dmi'