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/structures/plasticflaps.dm

@@ -10,6 +10,9 @@
 	CanAtmosPass = ATMOS_PASS_NO
 	var/state = PLASTIC_FLAPS_NORMAL
 
+/obj/structure/plasticflaps/opaque
+	opacity = TRUE
+
 /obj/structure/plasticflaps/examine(mob/user)
 	. = ..()
 	switch(state)
@@ -103,4 +106,3 @@
 	. = ..()
 	if (oldloc)
 		oldloc.air_update_turf(1)
-